WO2018173491A1 - Sintered compact and method for manufacturing sintered compact - Google Patents

Sintered compact and method for manufacturing sintered compact Download PDF

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Publication number
WO2018173491A1
WO2018173491A1 PCT/JP2018/003070 JP2018003070W WO2018173491A1 WO 2018173491 A1 WO2018173491 A1 WO 2018173491A1 JP 2018003070 W JP2018003070 W JP 2018003070W WO 2018173491 A1 WO2018173491 A1 WO 2018173491A1
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sintered body
body according
metal oxynitride
powder
crystal grains
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PCT/JP2018/003070
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French (fr)
Japanese (ja)
Inventor
信一 吉川
新 細野
友治 鱒渕
真志 猪口
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国立大学法人北海道大学
株式会社村田製作所
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Priority to JP2019507404A priority Critical patent/JP6850459B2/en
Publication of WO2018173491A1 publication Critical patent/WO2018173491A1/en

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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/549—Organic PV cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to a sintered body containing a metal oxynitride and a method for producing the same.
  • Patent Document 1 proposes a method in which an object to be fired and carbon are arranged close to each other and fired in a nitrogen gas atmosphere.
  • An object of the present invention is a sintered body containing a metal oxynitride, which is more sufficiently nitrided than before, a dielectric composition using the sintered body, and production of the sintered body Is to provide a method.
  • the sintered body according to the present invention includes an aggregate of a plurality of crystal grains containing a metal oxynitride and an amorphous material.
  • the amorphous is present at the interface between the crystal grains.
  • the plurality of crystal grains are made of polycrystal, and the amorphous is present along the crystal grain boundary of the polycrystal.
  • the amorphous material contains carbon
  • the amorphous material includes carbon and nitrogen.
  • the amorphous material includes at least one element of the same type as the metal element of the metal oxynitride.
  • the denseness of the aggregate is 65% or more.
  • the sintered compact can be used for applications utilizing physical properties that preferably have a high density. For example, it can be applied to a capacitor as a dielectric. More preferably, the denseness of at least a part of the aggregate is 80% or more.
  • the average value of the equivalent circle diameters of the crystal grains is 0.18 ⁇ m or more.
  • the average equivalent circle diameter of the crystal grains is 4.0 ⁇ m or less.
  • the plurality of crystal grains include a perovskite structure.
  • the metal of the metal oxynitride includes at least one of an alkaline earth metal and a rare earth metal.
  • the metal of the metal oxynitride is at least one selected from La, Ba, and Sr.
  • a first aspect of the dielectric composition according to the present invention is a dielectric composition comprising a sintered body constituted according to the present invention, wherein the sintered body is 5 MHz in an environment of 30 ° C. to 150 ° C.
  • the relative dielectric constant when an electric field of ⁇ 100 MHz is applied is 100 or more and 200 or less.
  • a second aspect of the dielectric composition according to the present invention is a dielectric composition comprising a sintered body configured according to the present invention, wherein the sintered body is within a temperature range of 30 ° C to 150 ° C.
  • the change rate of the relative permittivity when an electric field of 5 MHz to 100 MHz is applied due to the temperature change is within 10%.
  • the aggregate of the crystal grains of the metal oxynitride and the amorphous is ⁇ 50 when an electric field of 1 MHz is applied.
  • the rate of change of the relative dielectric constant is 3% or less due to the temperature change within the temperature range of 50 ° C to 50 ° C.
  • the capacitor according to the present invention includes a dielectric composition configured according to the present invention and a pair of electrodes opposed via the dielectric composition.
  • the photocatalyst composition according to the present invention includes a sintered body constituted according to the present invention.
  • the photoelectric conversion element according to the present invention includes a sintered body configured according to the present invention.
  • the gas sensor according to the present invention includes a sintered body configured according to the present invention.
  • the method for producing a sintered body according to the present invention is characterized in that the metal oxynitride and the sintering aid containing cyanamide are sintered in an atmosphere containing nitrogen while being in contact with each other.
  • the melting point of the cyanamide is lower than the nitrogen desorption temperature of the metal oxynitride. In this case, since nitrogen is more difficult to desorb, a sintered body with a higher nitrogen content can be provided more reliably.
  • BaCN 2 is preferably used as the cyanamide. In this case, a sintered body with a high nitrogen content can be provided more reliably.
  • the metal oxynitride is a material that dissolves in a liquid phase in which the cyanamide is melted.
  • a sintered body with a high nitrogen content can be provided more reliably.
  • the metal oxynitride is a kind selected from BaTaO 2 N and SrTaO 2 N.
  • the sintering is performed at a temperature of 880 ° C. or higher and 950 ° C. or lower. In this case, it is difficult to desorb nitrogen, and a sintered body with a high nitrogen content can be obtained.
  • the sintering aid is used in a proportion of 3 wt% or more and 50 wt% or less with respect to 100 wt% of the metal oxynitride. It is done. In this case, a sintered body having a high nitrogen content can be provided more reliably.
  • the sintering aid is in the form of powder or particles and is mixed with the metal oxynitride in the sintered state. Is done.
  • the sintered body and the method for producing the same according to the present invention it is possible to provide a sintered body rich in nitrogen as compared to a conventional sintered body made of a metal oxynitride that is partially nitrided. Can do. Therefore, a dielectric composition having excellent dielectric characteristics can be provided by the present invention.
  • a capacitor having a high capacitance can be provided using the dielectric composition. Furthermore, it becomes possible to provide a photocatalyst composition, a photoelectric conversion element, a gas sensor, and the like using the sintered body according to the present invention.
  • FIG. 1 is a diagram showing an XRD pattern of BaCN 2 used in Example 1 of the present invention.
  • Figure 2 is a proportion of the added bit BACn 2 is replaced by a metal oxynitride 100 wt% with respect to a drawing showing an XRD pattern of the sintered body using a composition of 30 wt%.
  • FIG. 3 is a 300 times SEM photograph of the sintered body obtained in the embodiment of the present invention.
  • FIG. 4 is a 10,000 times SEM photograph of the sintered body obtained in the embodiment of the present invention.
  • FIG. 5 is a STEM photograph of the sintered body obtained in Example 1.
  • 6 is a STEM photograph of another part of the sintered body obtained in Example 1.
  • FIG. FIG. 7 is an enlarged photograph of the STEM photograph shown in FIG.
  • FIG. 8 is a TEM photograph of a portion observed in the TEM-EDX spectrum analysis of the sintered body obtained in Example 1.
  • FIG. 9 is a diagram showing a TEM-EDX spectrum in a part of the photograph shown in FIG.
  • FIG. 10 is a diagram showing a TEM-EDX spectrum in another part of the photograph shown in FIG.
  • FIG. 11 is a TEM photograph of a TEM-EDX element mapping analysis site of the sintered body obtained in Example 1.
  • FIG. 12 is a diagram showing a TEM-EDX element mapping of carbon (C) atoms in the part of the photograph shown in FIG.
  • C carbon
  • FIG. 13 is a diagram showing a TEM-EDX element mapping of nitrogen (N) atoms in the part of the photograph shown in FIG.
  • FIG. 14 is a diagram showing a TEM-EDX element mapping of strontium (Sr) atoms in the part of the photograph shown in FIG.
  • FIG. 15 is a diagram showing a TEM-EDX element mapping of barium (Ba) atoms in the part of the photograph shown in FIG.
  • FIG. 16 is a diagram showing a TEM-EDX element mapping of tantalum (Ta) atoms in the part of the photograph shown in FIG.
  • FIG. 17 is a TEM photograph of a TEM-EDX element mapping analysis site in another part of the sintered body obtained in Example 1.
  • FIG. 18 is a diagram showing a TEM-EDX element mapping of carbon (C) atoms in the part of the photograph shown in FIG.
  • FIG. 19 is a diagram showing a TEM-EDX element mapping of nitrogen (N) atoms in the part of the photograph shown in FIG.
  • FIG. 20 is a diagram showing a TEM-EDX element mapping of strontium (Sr) atoms in the part of the photograph shown in FIG.
  • FIG. 21 is a diagram showing a TEM-EDX element mapping of barium (Ba) atoms in the part of the photograph shown in FIG.
  • FIG. 22 is a diagram showing a TEM-EDX element mapping of tantalum (Ta) atoms in the part of the photograph shown in FIG. FIG. 23A and FIG.
  • FIG. 23B are SEM photographs of magnifications of 10000 times and 50000 times of the sintered body of Example 1 after being etched.
  • FIG. 24 is a diagram showing the complex impedance characteristics of the sintered body obtained in Example 1.
  • FIG. 25 is a diagram showing the dielectric properties of the sintered body obtained in Example 1.
  • FIG. 26 is a diagram showing temperature characteristics of dielectric properties of the sintered body obtained in Example 1.
  • 27 (a) to 27 (c) are SEM photographs of magnifications of 2000 times, 5000 times, and 10000 times that of the sintered body obtained in Example 3.
  • FIG. 28A and 28B are STEM photographs of the sintered body obtained in Example 3.
  • FIG. 29 (a) to 29 (c) are STEM photographs of the sintered body obtained in Example 3.
  • FIG. 30 is a diagram showing a STEM-EDX spectrum in a part of the STEM photograph shown in FIG.
  • FIG. 31 is a diagram showing a STEM-EDX spectrum in another part of the STEM photograph shown in FIG. 32 is a view showing XRD patterns of respective portions in the sintered body obtained in Example 3.
  • FIG. Further, the numbers on the right side of Sr / Ba / Ta in the figure are the number ratios (at%) of the respective atoms of Sr, Ba, and Ta by XRF analysis of each part of the sintered body.
  • FIG. 33 is a diagram showing the complex impedance characteristics of the sintered body obtained in Example 3.
  • FIG. 34 is a diagram showing the dielectric properties obtained in Example 3.
  • FIG. 35 is a graph showing temperature characteristics of relative permittivity of the sintered body obtained in Example 3.
  • FIG. 36 is a graph showing the temperature characteristics of dielectric loss (tan ⁇ ) of the sintered body obtained in Example 3.
  • FIG. 37 is a diagram showing XRD patterns of BaTaO 2 N, SrTaO 2 N, and Sr 1-x Ba x TaO 2 N washed with nitric acid obtained in Example 4.
  • FIGS. 38A to 38C are diagrams for explaining SEM-EDX element mapping of Sr 1-x Ba x TaO 2 N particles washed with nitric acid obtained in Example 4.
  • FIG. 40 (a) and 40 (b) are SEM photographs of 20000 times and 50000 times of Sr 1-x Ba x TaO 2 N particles washed with nitric acid obtained in Example 4, respectively.
  • 41A and 41B are SEM photographs of 20000 times and 50000 times of Sr 1-x Ba x TaO 2 N particles washed with nitric acid obtained in Example 4, respectively.
  • FIG. 42 is a diagram showing an XRD pattern of a powder obtained by immersing the sintered body obtained in Example 5 and the sintered body in distilled water and then drying.
  • FIG. 43 (a) and 43 (b) are SEM photographs of 500 times and 10,000 times the sintered body obtained in Example 5, respectively.
  • 44 (a) and 44 (b) are SEM photographs of 500 times and 10,000 times the powder obtained by immersing the sintered body in distilled water and drying it in Example 5.
  • FIG. FIG. 45 is a diagram showing complex impedance characteristics of the sintered body obtained in Example 5.
  • FIG. 46 is a diagram showing the dielectric properties obtained in Example 5.
  • FIG. 47 is a STEM photograph of the sintered body obtained in Example 5.
  • FIG. 48 is a diagram showing STEM-EDX element mapping in the STEM photograph of the sintered body obtained in Example 5.
  • FIG. 49 is a view showing an XRD pattern of the sintered body obtained in Example 6.
  • FIG. 50 (a) to 50 (c) are SEM photographs of 500 times, 1000 times and 15000 times that of the sintered body obtained in Example 6.
  • FIG. FIG. 51 is a diagram showing the complex impedance characteristics of the sintered body obtained in Example 6.
  • FIG. 52 is a view showing dielectric properties obtained in Example 6.
  • FIG. 53 is a TEM photograph of the sintered body obtained in Example 6, and an electron diffraction pattern of a portion considered to be a crystal particle in the STEM photograph.
  • FIG. 54 is a diagram showing a STEM-EDX spectrum in a part of the TEM photograph shown in FIG.
  • FIG. 55 is a view showing a STEM-EDX spectrum in another part of the TEM photograph shown in FIG.
  • FIG. 56 is an XRD pattern of the sintered body obtained in Example 7.
  • the sintered body according to the present invention includes an aggregate of a plurality of crystal grains including metal oxynitride and amorphous.
  • the sintered body according to the present invention includes a plurality of crystal grains and an aggregate of amorphous.
  • the metal oxynitride in the plurality of crystal grains is not particularly limited, but various metal oxynitrides can be used.
  • As the metal an alkaline earth metal or a rare earth metal is preferably used. By using an alkaline earth metal or a rare earth metal, a sintered body having a high nitrogen content can be easily obtained.
  • the alkaline earth metal at least one of Ba and Sr is preferably used.
  • the rare earth metal La is preferably used. When Ba, Sr, or La is used, a sintered body with a still higher nitrogen content can be obtained with certainty.
  • the plurality of crystal grains containing the metal oxynitride are crystalline.
  • the sintered body according to the present invention includes the plurality of crystalline grains and an amorphous aggregate.
  • the amorphous material is made of an appropriate material that is not crystalline. Preferably, the amorphous is present at an interface between crystal grains.
  • the plurality of crystal grains are preferably made of polycrystal.
  • the amorphous material is preferably present between the polycrystalline grains. More specifically, the amorphous material is desirably present along the polycrystalline grain boundary.
  • the material constituting the amorphous material is not particularly limited, but preferably includes carbon, and more preferably includes carbon and nitrogen.
  • the amorphous may contain at least one element of the same kind as the metal element constituting the metal oxynitride described above. In that case, it can be considered that the above-described metal oxynitride is partially dissolved and re-precipitation causes sintering to progress, and therefore the amorphous portion is used to sinter the metal oxynitride. You can think of it as an assistant.
  • the denseness of the aggregate is preferably 65% or more.
  • the evaluation of the denseness is obtained by using image analysis, as will be described in Examples described later. If the denseness is 65% or more, it can be used for applications utilizing physical properties where it is preferable that the sintered body has high denseness.
  • the above-mentioned sintered body is used for a dielectric composition. More preferably, the denseness of at least a part of the aggregate is 80% or more.
  • the average value of the equivalent circle diameters of the crystal grains is preferably 0.18 ⁇ m or more. In that case, it can be considered that the crystal grains are bonded and grown with the oxynitride particles as the raw material of the sintered body.
  • the average value of the equivalent circle diameter of the crystal grains is preferably 4.0 ⁇ m or less.
  • the average value of the equivalent circle diameter is calculated based on image analysis software “A Image-kun” (for example, an image observed with a scanning electron microscope with a magnification of 30,000 times) obtained at a magnification that can determine the shape and size of particles. Asahi Kasei Engineering Co., Ltd. can be used.
  • magnification at this time for example, 5000 times, 10,000 times, or 30000 times are used.
  • brightness and contrast were adjusted so that the shape of the particles was conspicuous.
  • a binarization process was performed to extract only the particle portion.
  • the number, area, and equivalent circle diameter of particles were measured by “particle analysis” of image processing software.
  • crystal grains include a perovskite structure.
  • the sintered body according to the present invention has a high relative dielectric constant. Therefore, the sintered body of the present invention is suitably used for a dielectric composition.
  • the fact that the sintered body according to the present invention is excellent in the characteristics as a dielectric is that oxygen and nitrogen are sufficiently contained in the sintered body, and lattice defects of oxygen or nitrogen are sufficient. Therefore, it is considered that the insulating property is enhanced.
  • the sintered body obtained in the present invention exhibits orange to red in substantially the same manner as general oxynitride powder. Therefore, it can be understood that a sintered body having a high nitrogen content is obtained with little nitrogen desorption.
  • the orange to red color tone indicates that the band gap energy is in the visible light region. Therefore, the sintered body and its constituent particles according to the present invention can be suitably used for a photocatalyst composition, a photoelectric conversion element and the like. Further, since nitrogen is present on the surface, it is possible to provide a gas sensor that can measure a gas that cannot be measured by a conventional oxide sensor.
  • the metal oxynitride and the sintering aid containing cyanamide are sintered in an atmosphere containing nitrogen while being in contact with each other.
  • a sintered body having a high nitrogen content can be obtained.
  • the melting point of the cyanamide is preferably lower than the nitrogen desorption temperature of the metal oxynitride. Thereby, nitrogen desorption is less likely to occur during sintering.
  • the cyanamide is not particularly limited, preferably, can be used as the BaCN 2, SrCN 2, CaCN 2 , more preferably, bit BACn 2 is used.
  • the BaCN 2 is used as a sintering aid, and the crystal structure of BaCN 2 is not observed in the obtained sintered body. That is, an amorphous part exists between crystal grains made of metal oxynitride.
  • the metal oxynitride is preferably a material that dissolves in a liquid phase in which cyanamide is melted. Thereby, a sintered body with a high nitrogen content can be provided more reliably.
  • Such metal oxynitride is not particularly limited, for example, BaTaO 2 N and SrTaO 2 N is used.
  • the melting point of BaCN 2 is around 900 ° C.
  • the weight change start temperature accompanied by nitrogen desorption of SrTaO 2 N is around 1000 ° C. Therefore, SrTaO 2 N hardly desorption occurs nitrogen, at temperatures around 900 ° C., bit BACn 2 present around the SrTaO 2 N is changed to a liquid phase. Therefore, the phenomenon that SrTaO 2 N particles are dissolved in the liquid phase BaCN 2 and re-deposited is repeated. That is, SrTaO 2 N is sintered by liquid phase sintering. The SrTaO 2 N particles are bonded to each other by repeating the dissolution and reprecipitation phenomenon, and the grain growth proceeds. As a result, a sintered body of Sr 1-x Ba x TaO 2 N can be obtained.
  • SrTaO 2 N sintering has required a high temperature of 1400 ° C. or higher.
  • firing can be performed at a low temperature of about 800 ° C. to 900 ° C. Therefore, nitrogen desorption is unlikely to occur during firing. As a result, it is possible to obtain a sintered body with an increased nitrogen content.
  • the desorption temperature of nitrogen from SrTaO 2 N is around 1000 ° C. Therefore, in the production method of the present invention, firing is preferably performed at a temperature lower than 1000 ° C. More preferably, in the method for producing a sintered body according to the present invention, at the time of firing, the metal oxynitride and the sintering aid containing cyanamide are in contact with each other at a temperature of 880 ° C. or higher and 950 ° C. or lower. It is preferable to heat with. Within this temperature range, nitrogen desorption is less likely to occur.
  • the aspect in which the metal oxynitride and the sintering aid containing cyanamide are brought into contact with each other is not particularly limited.
  • a metal oxynitride and a sintering aid containing cyanamide may be mixed.
  • a sintering aid containing cyanamide may be placed on the metal oxynitride.
  • the sintered body is obtained by a single firing. In this case, nitrogen desorption is less likely to occur.
  • nitrogen is hardly desorbed by firing at a temperature lower than the temperature at which nitrogen is desorbed and by firing in a nitrogen atmosphere as described above. .
  • the sintering aid is preferably in the form of powder or particles.
  • the metal oxynitride can be easily mixed, and the sintering can be performed in a mixed state. Therefore, a sintered body with a high nitrogen content can be obtained more reliably.
  • the amount of the sintering aid used is not particularly limited, but it is preferably 3% by weight or more, more preferably 5% by weight or more based on 100% by weight of the metal oxynitride. More preferably, it is used at a ratio of 10% by weight or more. Further, the amount of the sintering aid used is desirably 50% by weight or less based on 100% by weight of the metal oxynitride. If it is in the said range, a sintered compact with much nitrogen content can be obtained still more reliably.
  • the dielectric composition comprising the sintered body according to the present invention preferably has a relative dielectric constant of 100 or more and 200 or less when an electric field of 5 MHz to 100 MHz is applied in an environment of 30 ° C. to 150 ° C. .
  • the dielectric composition comprising the sintered body according to the present invention preferably has a change rate of a relative dielectric constant within 10% due to a temperature change within a temperature range of 30 ° C. to 150 ° C.
  • the dielectric composition according to the present invention can be suitably used for a capacitor, for example.
  • the aggregate of the metal oxynitride crystal grains and the amorphous material has a dielectric constant caused by a temperature change within a temperature range of ⁇ 50 ° C. to 50 ° C. when an electric field of 1 MHz is applied.
  • the rate of change of the rate is within 3%. In this case, it is possible to provide a capacitor having a small change in relative dielectric constant due to a temperature change.
  • the structure of the capacitor according to the present invention is not particularly limited as long as it includes the dielectric composition according to the present invention and a pair of electrodes opposed via the dielectric composition.
  • one electrode of the pair of electrodes may be provided on one surface of the dielectric composition, and the other electrode may be provided on the other surface of the dielectric composition.
  • a pair of electrodes may be provided on the same surface of the dielectric composition with a gap therebetween.
  • the band gap energy is preferably in the visible light region, that is, in the region of 1.65 eV to 3.26 eV. This is because the photocatalytic properties can be enhanced because the energy range of available sunlight increases.
  • the sintered body obtained by the present invention exhibits a color tone of orange to red. Therefore, it is estimated that the band gap energy is in the visible light region. Therefore, the sintered body according to the present invention can be suitably used for the photocatalyst composition.
  • the photoelectric conversion material has a band gap energy in the visible light region, and it is preferable that there are few impurities. Therefore, the sintered body of the present invention can be suitably used for the photoelectric conversion element.
  • Example 1 In the conventional metal oxynitride sintered body, nitrogen is desorbed and becomes a semiconductor. Therefore, electric resistance is low and it was difficult to use as a dielectric.
  • the sintered body obtained in the present invention contains a large amount of nitrogen and exhibits characteristics as an insulator, that is, a dielectric. Therefore, the sintered body of the present invention can be suitably used for the dielectric composition.
  • the obtained Sr 2 Ta 2 O 7 powder was placed on a boat made of aluminum oxide (Al 2 O 3 ) and provided in a tubular furnace having a quartz glass furnace tube. Ammonia gas was allowed to flow through the furnace core tube at a flow rate of 100 ml / min and heated at 1000 ° C. for 80 hours to synthesize SrTaO 2 N powder.
  • the temperature rising rate by the tubular furnace temperature controller was 5 ° C./min, and the temperature lowering rate was 3 ° C./min.
  • the obtained SrTaO 2 N powder was subjected to crystal analysis using a powder X-ray diffraction (XRD) apparatus. As a result, it was confirmed that it coincided with the inorganic crystal structure data of SrTaO 2 N.
  • XRD powder X-ray diffraction
  • the primary particle size of the obtained powder was measured using a scanning electron microscope (SEM). As a result, the particle size was about 40 nm to 150 nm. The average particle size was 90 nm.
  • BaCN 2 powder Barium carbonate (BaCO 3 ) was placed on a boat made of aluminum oxide and placed in the same tubular furnace used in (1). Ammonia was flowed into the furnace tube at a flow rate of 50 ml / min and heated at a temperature of 900 ° C. for 10 hours to obtain a powder. The temperature increase / decrease rate was 5 ° C./min.
  • the obtained powder was subjected to crystal analysis using an XRD apparatus. The results are shown in FIG.
  • the crystal phase of the obtained powder was different from the existing BaCN 2 powder diffraction data file (JCPDS 51-542). Therefore, the crystal phase of the obtained powder is considered to be a novel crystal phase.
  • the elemental composition of the obtained powder was analyzed using inductively coupled plasma emission spectroscopy (ICP-AES). As a result, it was found that Ba was contained at a ratio of 74 wt% or more and 77 wt% or less. Further, it was found by combustion composition analysis that C and N were contained by 6.5% by weight and 15.3% by weight, respectively.
  • ICP-AES inductively coupled plasma emission spectroscopy
  • composition of the obtained powder was estimated to be bit BACn 2.
  • Composition assuming a bit BACn 2 was examined by XRD crystal structure of the powder. The density was determined based on the estimated crystal structure. As a result, the theoretical density was estimated to be 4.53 g / cm 3 .
  • the molded body was taken out from the mold.
  • the removed molded body was vacuum packed and pressurized at 150 MPa using an isotropic isostatic press.
  • the shaped body taken out after pressurization was placed on an aluminum oxide boat using the SrTaO 2 N powder synthesized in (1) as a filling powder, and the tubular furnace used in (1) and (2) Placed in. While flowing nitrogen gas through the furnace tube at a flow rate of 50 ml / min, heating was performed at a temperature of 900 ° C. for 30 hours. Thereby, a sintered body was obtained.
  • the temperature rising rate was 5 ° C./min and the temperature lowering rate was 3 ° C./min.
  • the diameter and thickness of the molded body after being pressed were 6 mm and 2 mm in diameter, whereas the diameter of the obtained sintered body was 5.4 mm and the thickness was 1.6 mm. It was. From the volume and weight of the molded body and the sintered body, it was found that the density of the obtained sintered body was about 42% higher than that of the molded body.
  • the density of the sintered body was about 5.6 g / cm 3 .
  • the density of this sintered body was 70.2% of 7.975 g / cm 3 , which is the calculated density described in the inorganic crystal structure data (ICSD 95373).
  • the Therefore, the density of the sintered body was 78% of the estimated density of 7.18 g / cm 3 .
  • the diffraction peak positions are distributed at an angle close to SrTaO 2 N. Therefore, it is presumed that the main crystal phase of this sintered body is a perovskite phase.
  • the obtained sintered body was fractured, and the fractured surface was observed using SEM.
  • This SEM photograph is shown in FIGS. In the 300 times magnified photograph shown in FIG. 3, the region where the particles are present densely and the voids having a width of about 50 ⁇ m are distributed without regularity. In addition, in the observation photograph with a magnification of 10,000 times shown in FIG.
  • the SEM observation photograph used an image with a magnification of 300 times or 500 times.
  • the range of the acquired image was width 392 ⁇ m ⁇ height 284 ⁇ m in the case of 300 times, and width 258 ⁇ m ⁇ height 181 ⁇ m in the case of 500 times.
  • the image has many irregularities due to the fracture surface of the fired body.
  • the area that was originally thought to be a void can be said to be a place where a dark hole or a fragment of a sintered body generated due to breakage has entered, so the brightness and contrast were adjusted so that these voids were conspicuous. .
  • Binary processing was performed using image processing software “A Image-kun”, and only voids were extracted. If extraction by the binarization process of “A image” was not complete, it was manually compensated.
  • the total area, the number, the void area ratio, and the area of the measurement range were measured by the “total area / number measurement” of “A image-kun”.
  • the area ratio of the voids in the image area obtained by SEM observation was 20.0% to 32.0%. Since the compactness of the sintered body was 100-void area ratio, it was determined to be 68.0% to 80.0%.
  • the obtained sintered body was processed using a focused ion beam (FIB), and observation and element distribution analysis were performed using a scanning transmission electron microscope (STEM) and energy dispersive X-ray analysis (EDX).
  • 5 and 6 are STEM photographs of the sintered body.
  • FIG. 7 shows the STEM photograph shown in FIG. 5 and the electron diffraction patterns of the part that seems to be crystal grains and the part that seems to be amorphous.
  • FIG. 8 is a TEM photograph of a portion observed in the TEM-EDX spectrum analysis of the sintered body
  • FIGS. 9 and 10 are TEM-EDX spectra of a particle portion and an interparticle portion.
  • 11 to 22 are diagrams showing TEM-EDX element mapping images of the sintered body.
  • FIG. 11 and FIG. 17 are TEM photographs of observation points in the TEM-EDX element mapping analysis. A large amount of Sr and Ta is distributed in the crystal particle portion, and Ba and N are detected in addition. On the other hand, in the amorphous part, a large amount of Ba, C, and N is distributed, and trace amounts of Sr and Ta are detected.
  • FIG. 23A and FIG. 23B are SEM photographs of the fracture surface. Compared to the SEM photograph at a magnification of 10000 in FIG. 4, in FIG.
  • angular particles having a particle size of about 80 nm to 400 nm and an average particle size of about 200 nm are distributed while being bonded to each other.
  • the average value of the equivalent circle diameter was determined to be 237 nm.
  • the void between the particles is considered to be a portion where amorphous exists. Therefore, the portion where the amorphous material was present is considered to be about 1 ⁇ m at most.
  • FIG. 24 is a diagram illustrating complex impedance characteristics. From FIG. 24, it was found that the complex impedance is in the region of several M ⁇ , and the sintered body has sufficient insulation. As shown in FIG. 25, the relative dielectric constant ( ⁇ r ) exists in the region of 60 or more and 200 or less regardless of the frequency, and the dielectric loss is 7 ⁇ 10 ⁇ 2 (7%) or more and 3 ⁇ 10. -1 (30%) and below.
  • the increase in relative dielectric constant in the temperature range of 30 ° C. to 150 ° C. was divided by the relative dielectric constant at 30 ° C.
  • the change rate of the dielectric constant was 10.7, 9.3, 6.5, 5.6 (%) at frequencies of 5, 10, 50, and 100 MHz, respectively.
  • the dielectric loss varied between 0.08 (8%) and 0.2 (20%).
  • Example 2 Is the amount for SrTaO 2 N of bit BACn 2 except that the 50 parts by weight, in the same manner as in Example 1 to obtain a sintered body. Similar to the sintered body obtained in Example 1, the obtained sintered body was contracted and hard as compared with the formed body after pressurization. In addition, the sintered body obtained in Example 2 was more reddish than the sintered body obtained in Example 1.
  • the sintered body obtained in Example 2 has a strong redness due to the following reason. That is, it is considered that x is larger in the case of Sr 1-x Ba x TaO 2 N than in the case of the first embodiment. In other words, it is considered that the substitution from Sr to Ba is further advanced at the Sr site in SrTaO 2 N.
  • Example 3 On the forming of SrTaO 2 N obtained in Example 1 (1), with 30% of the weight of the molded article, placing the molded article of the bit BACn 2, 2 hours, nitrogen gas at a temperature of 900 ° C. And heated. Thereby, a sintered body was obtained.
  • the obtained sintered body was red and hard. A slightly bright red or white layer was observed on the upper surface of the sintered body. When this sintered body was dry-polished, the polished surface was glossy.
  • FIGS. 29 (a) to 29 (c) show an enlarged main part thereof.
  • FIG. 28 (a), FIG. 28 (b) and FIGS. 29 (a) to 29 (c) show that the particles are bound by another substance.
  • FIG. 30 shows the STEM-EDX spectrum of the part seen as the crystal grain of the STEM photograph shown in FIG. 29 (a), and FIG. 31 shows the STEM-EDX spectrum of the part seen as the binding substance part.
  • FIG. 32 is a diagram showing an XRD pattern of each part. Further, the numbers on the right side of Sr / Ba / Ta in the figure are the number ratios (at%) of the respective atoms of Sr, Ba, and Ta according to the fluorescent X-ray (XRF) analysis of each part of the sintered body. From the top surface to the bottom surface, it can be seen that the main crystal phase has a perovskite structure and shows a diffraction pattern of Sr 1-x Ba x TaO 2 N.
  • FIG. 33 is a diagram showing the complex impedance characteristic of this sintered body.
  • FIG. 33 confirms that the sintered body has a resistance of several M ⁇ and has an insulating property.
  • the dielectric properties of the sintered body were evaluated in the same manner as in Example 1. The results are shown in FIG. From FIG. 34, it is understood that the relative dielectric constant ( ⁇ r ) is around 100 and the dielectric loss (tan ⁇ ) varies between 10 ⁇ 1 (10%) and 0.7 (70%). .
  • the temperature dependence of dielectric properties is shown in FIGS. Table 1 below shows the amount of increase in the relative permittivity ( ⁇ r ) for each frequency of the applied electric field in the temperature range of ⁇ 50 ° C. to 50 ° C. and 100 ° C.
  • the amount of change in relative permittivity ( ⁇ r ) due to temperature change in the above temperature range is 6.22%, 4.23%, 2.92%, and 1kHz at frequencies of 1 kHz, 10 kHz, 100 kHz, and 1 MHz, respectively. 1.94%.
  • the sintering aid cyanamide may not be used in combination with a metal oxynitride. That is, the sintering aid only needs to be in contact with the metal oxynitride.
  • Example 4 After mixing 200 mg of the SrTaO 2 N powder synthesized in (1) of Example 1 and 300 mg of BaCN 2 powder, the mixture was placed in an aluminum oxide crucible, and the temperature was 900 ° C. in the same manner as in Example 1. And heated in nitrogen gas for 30 hours. After the heat treatment, a reddish brown solid was formed on the bottom of the crucible.
  • the solidified product was taken out and immersed in nitric acid having a concentration of 1 mol / L for 15 hours. As a result, red fine powder precipitated on the bottom of the container containing nitric acid. A precipitate was obtained by filtration and washed with distilled water to obtain a sample powder.
  • the composition of the sample powder was analyzed using XRF. As a result, Sr, Ba, and Ta were included at a ratio of 41.9 (2): 7.94 (4): 50.2 (3). The ratio of Sr + Ba almost coincided with the ratio of Ta.
  • the elemental composition of the filtrate was analyzed using ICP-AES. As a result, the presence of Sr, Ba and a small amount of Ta was confirmed. Therefore, it is estimated that the amorphous part of the sintered body produced in Example 1 contains not only the original BaCN 2 but also Sr and Ta dissolved from the SrTaO 2 N oxynitride particles.
  • the sample powder was subjected to XRD analysis.
  • the results are shown in FIG. FIG. 37 shows that this sample powder has the same perovskite crystal as SrTaO 2 N and BaTaO 2 N.
  • the diffraction peak position of the sample powder has a diffraction peak position of SrTaO 2 N, were present during the diffraction peak position of the BaTaO 2 N. From the results of the XRF analysis and the XRD analysis, it was found that the sample powder was Sr 1-x Ba x TaO 2 N.
  • the element distribution was analyzed using EDX in which the sample powder was mounted on an SEM. Element mapping images are shown in FIGS. 38 (a) to 38 (c) and FIGS. 39 (a) to 39 (c). It was confirmed that Sr, Ba, Ta, N and O were uniformly distributed.
  • 40 (a), 40 (b), 41 (a), and 41 (b) are SEM photographs of powder particles washed with nitric acid as described above.
  • the primary particle size of the particles is about 0.1 ⁇ m to 3 ⁇ m, and the primary particles are firmly bonded to each other. It seemed to be.
  • the size of the secondary particles was about several ⁇ m.
  • Example 5 This example differs from Example 1 in that LaTaON 2 is used as the metal oxynitride. Details of the present embodiment will be described below.
  • La 2 O 3 Lanthanum oxide (La 2 O 3 ) powder and lanthanum oxide and an equimolar amount of tantalum oxide (Ta 2 O 5 ) were mixed in an ethanol dispersion medium. After drying in the air, heat treatment was performed for 20 hours at a temperature of 1400 ° C. in an air atmosphere using an electric furnace. Thereby, LaTaO 4 powder was obtained.
  • the obtained LaTaO 4 powder was placed on a boat made of aluminum oxide (Al 2 O 3 ) and provided in a tubular furnace having a quartz glass core tube. Ammonia gas was allowed to flow through the furnace tube at a flow rate of 100 ml / min and heated at 1000 ° C. for 15 hours to synthesize LaTaON 2 powder.
  • the temperature rising rate by the tubular furnace temperature controller was 5 ° C./min, and the temperature lowering rate was 3 ° C./min.
  • the obtained LaTaON 2 powder was crystallized using a powder X-ray diffraction (XRD) apparatus. As a result, it was confirmed to be consistent with LaTaON 2 inorganic crystal structure data.
  • XRD powder X-ray diffraction
  • LaTaON 2 powder mixing the bit BACn 2 powder obtained in Example 1 (2) to produce a molded body in the same manner as in Example 1.
  • the addition amount of the BaCN 2 powder to the LaTaON 2 powder was 30 parts by weight.
  • the molar ratio of LaTaON 2 to BaCN 2 corresponds to 62 mol%: 38 mol%.
  • the molded body was heated at a temperature of 915 ° C. for 30 hours while flowing nitrogen gas.
  • the obtained sintered body was solidified. Furthermore, when this sintered body was immersed in distilled water for 1 day, the sintered body collapsed into a powder form. The powder was collected and dried using a centrifuge.
  • FIG. 42 is a view showing an XRD pattern of a powder obtained by immersing the sintered body obtained in Example 5 and the sintered body in distilled water and then drying.
  • the sintered body is composed of LaTaON 2 and Ba 2 LaTaO 6 .
  • 43 (a) and 43 (b) are SEM photographs of 500 times and 10,000 times the sintered body obtained in Example 5, respectively.
  • 44 (a) and 44 (b) are SEM photographs of 500 times and 10,000 times the powder obtained by immersing the sintered body in distilled water and drying it in Example 5.
  • FIG. 43 (a) and 43 (b) are SEM photographs of 500 times and 10,000 times the powder obtained by immersing the sintered body in distilled water and drying it in Example 5.
  • the particles inside the sintered body are covered with a film-like object.
  • powder particles obtained by immersing the sintered body in distilled water and drying were not covered with a film-like substance, and the shape of each particle was clearly observed. From these results, it was found that the amorphous component covered the surface of the crystal particles.
  • the particle size distribution of the oxynitride particles in the sintered body was analyzed using the image analysis software “A image-kun” on a plurality of SEM photographs of the fracture surface in the same manner as in Example 1. As a result, the average circle equivalent diameter was determined to be 1950 nm.
  • FIG. 45 is a diagram showing the complex impedance characteristic of this sintered body.
  • FIG. 45 confirmed that the sintered body had a resistance of several M ⁇ and had insulating properties.
  • the dielectric properties of the sintered body were evaluated in the same manner as in Example 1. The results are shown in FIG. From FIG. 46, the relative dielectric constant ( ⁇ r ) is about 10 or more and 40 or less, and the dielectric loss (tan ⁇ ) varies between 0.1 (10%) and 0.6 (60%) or less. I understand that.
  • the sintered body of the present invention such as for example LaTaON 2, may also be used metal oxynitride non SrTaO 2 N.
  • the fracture surface of the sintered body was subjected to FIB processing and STEM-EDX analysis was performed.
  • FIG. 47 shows a STEM observation photograph and an electron beam diffraction image. Further, STEM-EDX element mapping is shown in FIG.
  • Example 6 This example differs from Example 1 in that BaTaO 2 N is used as the metal oxynitride. Details of the present embodiment will be described below.
  • Barium carbonate (BaCO 3 ) powder and 0.5 molar equivalent of tantalum oxide (Ta 2 O 5 ) with respect to 1.02 molar equivalent of barium carbonate were mixed in an ethanol dispersion medium.
  • the powder obtained by drying in air was placed on a boat made of aluminum oxide (Al 2 O 3 ) and provided in a tubular furnace having a quartz glass furnace tube. Ammonia gas was allowed to flow through the furnace tube at a flow rate of 100 ml / min and heated at 950 ° C. for 80 hours to synthesize BaTaO 2 N powder.
  • the temperature rising rate by the tubular furnace temperature controller was 5 ° C./min, and the temperature lowering rate was 3 ° C./min.
  • the obtained BaTaO 2 N powder was subjected to crystal analysis using a powder X-ray diffraction (XRD) apparatus. As a result, it was confirmed that it coincided with the inorganic crystal structure data of BaTaO 2 N.
  • XRD powder X-ray diffraction
  • the BaTaO 2 N powder and the BaCN 2 powder obtained in (2) of Example 1 were mixed, and a compact was produced in the same manner as in Example 1. At this time, the amount of BaCN 2 powder added to the BaTaO 2 N powder was 10 parts by weight.
  • the molded body was heated at a temperature of 900 ° C. for 10 hours while flowing nitrogen gas. The obtained sintered body was solidified.
  • FIG. 49 is a view showing an XRD pattern of the sintered body obtained in Example 6.
  • the sintered body contains an amorphous component derived from BaCN 2 .
  • 50 (a) to 50 (c) are SEM photographs of 500 times, 1000 times, and 15000 times that of the sintered body obtained in Example 6.
  • FIG. 1
  • FIG. 51 is a diagram showing the complex impedance characteristic of this sintered body. From FIG. 51, it was confirmed that the sintered body had a resistance of several M ⁇ and had insulating properties.
  • the dielectric properties of the sintered body were evaluated in the same manner as in Example 1. The results are shown in FIG. From FIG. 52, the relative dielectric constant ( ⁇ r ) is about 4 or more and 40 or less, and the dielectric loss (tan ⁇ ) varies between 0.06 (6%) or more and 0.7 (70%) or less. I understand that. From this result, it can be seen that this sintered body can be suitably used for a dielectric composition.
  • the fracture surface of the sintered body was subjected to FIB processing and TEM-EDX analysis was performed.
  • FIG. 53 shows a TEM observation photograph and an electron diffraction image of a portion seen as a crystal grain in the photograph.
  • FIG. 54 shows a TEM-EDX spectrum of a part seen as a crystal grain in the TEM photograph shown in FIG. 53
  • FIG. 55 shows a TEM-EDX spectrum of a part seen as a binder substance part.
  • the sintered body of the present invention for example BaTaO such 2 N, may also be used metal oxynitride non SrTaO 2 N.
  • Example 7 Lanthanum oxide (La 2 O 3 ) powder and 2 molar equivalents of titanium oxide (TiO 2 ) powder with respect to 1 molar equivalent of lanthanum oxide were mixed in an ethanol dispersion medium. The obtained mixed powder was heat-treated at a temperature of 1200 ° C. for 30 hours. Thereby, La 2 Ti 2 O 7 powder was obtained.
  • La 2 Ti 2 O 7 powder was flowed with ammonia gas and heated at 980 ° C. for 20 hours in substantially the same manner as in Example 1 to synthesize LaTiO 2 N powder.
  • a LaTiO 2 N powder and the BaCN 2 powder obtained in (1) of Example 1 were mixed, and a compact was produced in the same manner as in Example 1.
  • the addition amount of the BaCN 2 powder to the LaTiO 2 N powder was 10 parts by weight, 20 parts by weight or 30 parts by weight.
  • the molded body was heated at a temperature of 950 ° C. for 10 hours while flowing nitrogen gas.
  • the obtained fired product was not solidified and was like a powder compact.
  • FIG. 56 is an XRD pattern of the sintered body obtained in Example 7.
  • the sintered body was composed of lanthanum oxide (La 2 O 3 ), titanium nitride (TiN), and dibarium titanate (Ba 2 TiO 4 ). Unlike the examples relating to sintered bodies of SrTaO 2 N + BaCN 2 , BaTaO 2 N + BaCN 2 and LaTaON 2 + BaCN 2 , it was found that a solidified sintered body could not be obtained.
  • LaTiO 2 N is partly due to the desorption and thermal decomposition of N from 800 ° C. Before BaCN 2 melts and begins to act as a sintering aid, this thermal decomposition produces another type of compound phase such as TiN or La 2 O 3, so LaTiO 2 N undergoes sintering using BaCN 2 do not do.

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Abstract

Provided is a sintered compact that comprises a metal oxynitride and is nitrided substantially more than conventional sintered compacts. This sintered compact comprises a mass of a plurality of crystal grains including metal oxynitride and an amorphous material. Also provided is a method for manufacturing the sintered compact by sintering, in an atmosphere containing nitrogen, the metal oxynitride and a sintering additive containing a cyanamide in contact with each other.

Description

焼結体及び焼結体の製造方法Sintered body and method of manufacturing the sintered body
　本発明は、金属酸窒化物を含む焼結体及びその製造方法に関する。 The present invention relates to a sintered body containing a metal oxynitride and a method for producing the same.
　従来、ペロブスカイト構造を有する金属酸窒化物焼結体の製造に際しては、アンモニアガスを利用する方法が知られている。 Conventionally, a method using ammonia gas is known for the production of a metal oxynitride sintered body having a perovskite structure.
　しかしながら、アンモニアガスは、製造装置を腐食させるおそれがあった。そのため、下記の特許文献１では、被焼成物と炭素とを近接配置し、窒素ガス雰囲気下で焼成する方法が提案されている。 However, ammonia gas may corrode the manufacturing equipment. Therefore, Patent Document 1 below proposes a method in which an object to be fired and carbon are arranged close to each other and fired in a nitrogen gas atmosphere.
特許第３０７８２８７号公報Japanese Patent No. 3078287
　特許文献１に記載の製造方法では、アンモニアガスを用いないため、製造装置が腐食し難い。しかしながら、特許文献１の段落［００２３］に記載のように、得られた焼結体は誘電体となっていない。これは、焼結体全体が十分に窒化されていないためと考えられる。すなわち、ごく一部のみが酸窒化物となっており、残りの大部分は酸窒化物になっていないと考えられる。 In the manufacturing method described in Patent Document 1, since ammonia gas is not used, the manufacturing apparatus is hardly corroded. However, as described in paragraph [0023] of Patent Document 1, the obtained sintered body is not a dielectric. This is presumably because the entire sintered body is not sufficiently nitrided. That is, it is considered that only a small part is oxynitride, and the remaining most is not oxynitride.
　本発明の目的は、金属酸窒化物を含む焼結体であって、従来よりも十分に窒化されている焼結体、該焼結体を用いた誘電体組成物及び該焼結体の製造方法を提供することである。 An object of the present invention is a sintered body containing a metal oxynitride, which is more sufficiently nitrided than before, a dielectric composition using the sintered body, and production of the sintered body Is to provide a method.
　本発明に係る焼結体は、金属酸窒化物を含む複数の結晶粒と、非晶質との集合体を含む。 The sintered body according to the present invention includes an aggregate of a plurality of crystal grains containing a metal oxynitride and an amorphous material.
　本発明に係る焼結体のある特定の局面では、前記非晶質が、前記結晶粒間の界面に存在している。 In a specific aspect of the sintered body according to the present invention, the amorphous is present at the interface between the crystal grains.
　本発明に係る焼結体の他の特定の局面では、前記複数の結晶粒が多結晶からなり、前記非晶質が前記多結晶の結晶粒界に沿って存在する。 In another specific aspect of the sintered body according to the present invention, the plurality of crystal grains are made of polycrystal, and the amorphous is present along the crystal grain boundary of the polycrystal.
　本発明に係る焼結体の別の特定の局面では、前記非晶質が炭素を含む。 In another specific aspect of the sintered body according to the present invention, the amorphous material contains carbon.
　本発明に係る焼結体のさらに他の特定の局面では、前記非晶質が、炭素と窒素とを含む。 In yet another specific aspect of the sintered body according to the present invention, the amorphous material includes carbon and nitrogen.
　本発明に係る焼結体のさらに他の特定の局面では、前記非晶質は、前記金属酸窒化物の金属元素と同種の元素を少なくとも１つ含む。 In yet another specific aspect of the sintered body according to the present invention, the amorphous material includes at least one element of the same type as the metal element of the metal oxynitride.
　本発明に係る焼結体の別の特定の局面では、前記集合体の緻密性が６５％以上である。この場合には、焼結体の緻密性が高いことが好ましい物性を活用した応用に用いることができる。例えば、誘電体としてキャパシタへ応用することが挙げられる。より好ましくは、前記集合体の少なくとも一部の緻密性が、８０％以上である。 In another specific aspect of the sintered body according to the present invention, the denseness of the aggregate is 65% or more. In this case, the sintered compact can be used for applications utilizing physical properties that preferably have a high density. For example, it can be applied to a capacitor as a dielectric. More preferably, the denseness of at least a part of the aggregate is 80% or more.
　本発明に係る焼結体のさらに他の特定の局面では、前記結晶粒の円相当径の平均値が０．１８μｍ以上である。 In yet another specific aspect of the sintered body according to the present invention, the average value of the equivalent circle diameters of the crystal grains is 0.18 μm or more.
　本発明に係る焼結体のさらに他の特定の局面では、前記結晶粒の円相当径の平均値が４．０μｍ以下である。 In yet another specific aspect of the sintered body according to the present invention, the average equivalent circle diameter of the crystal grains is 4.0 μm or less.
　本発明に係る焼結体の別の特定の局面では、前記複数の結晶粒が、ペロブスカイト構造を含む。 In another specific aspect of the sintered body according to the present invention, the plurality of crystal grains include a perovskite structure.
　本発明に係る焼結体の別の特定の局面では、前記金属酸窒化物の金属は、アルカリ土類金属及び希土類金属のうち少なくとも一方を含む。 In another specific aspect of the sintered body according to the present invention, the metal of the metal oxynitride includes at least one of an alkaline earth metal and a rare earth metal.
　本発明に係る焼結体のさらに他の特定の局面では、前記金属酸窒化物の金属は、Ｌａ、Ｂａ及びＳｒから選択される少なくとも一種である。 In yet another specific aspect of the sintered body according to the present invention, the metal of the metal oxynitride is at least one selected from La, Ba, and Sr.
　本発明に係る誘電体組成物の第１の態様は、本発明に従って構成された焼結体からなる誘電体組成物であって、前記焼結体は、３０℃～１５０℃の環境において、５ＭＨｚ～１００ＭＨｚの電場が印加された際の比誘電率が、１００以上、２００以下である。 A first aspect of the dielectric composition according to the present invention is a dielectric composition comprising a sintered body constituted according to the present invention, wherein the sintered body is 5 MHz in an environment of 30 ° C. to 150 ° C. The relative dielectric constant when an electric field of ˜100 MHz is applied is 100 or more and 200 or less.
　本発明に係る誘電体組成物の第２の態様は、本発明に従って構成された焼結体からなる誘電体組成物であって、前記焼結体は、３０℃～１５０℃の温度範囲内での温度変化による、５ＭＨｚ～１００ＭＨｚの電場が印加された際の比誘電率の変化率が１０％以内である。 A second aspect of the dielectric composition according to the present invention is a dielectric composition comprising a sintered body configured according to the present invention, wherein the sintered body is within a temperature range of 30 ° C to 150 ° C. The change rate of the relative permittivity when an electric field of 5 MHz to 100 MHz is applied due to the temperature change is within 10%.
　本発明に係る誘電体組成物の他の特定の局面では、前記金属酸窒化物の前記結晶粒と、前記非晶質との前記集合体は、１ＭＨｚの電場が印加された場合に、－５０℃～５０℃の温度範囲内での温度変化による、比誘電率の変化率が３％以内である。 In another particular aspect of the dielectric composition according to the present invention, the aggregate of the crystal grains of the metal oxynitride and the amorphous is −50 when an electric field of 1 MHz is applied. The rate of change of the relative dielectric constant is 3% or less due to the temperature change within the temperature range of 50 ° C to 50 ° C.
　本発明に係るキャパシタは、本発明に従って構成された誘電体組成物と、前記誘電体組成物を介して対向されている一対の電極とを備える。 The capacitor according to the present invention includes a dielectric composition configured according to the present invention and a pair of electrodes opposed via the dielectric composition.
　本発明に係る光触媒組成物は、本発明に従って構成された焼結体を含む。 The photocatalyst composition according to the present invention includes a sintered body constituted according to the present invention.
　本発明に係る光電変換素子は、本発明に従って構成された焼結体を含む。 The photoelectric conversion element according to the present invention includes a sintered body configured according to the present invention.
　本発明に係るガスセンサは、本発明に従って構成された焼結体を含む。 The gas sensor according to the present invention includes a sintered body configured according to the present invention.
　本発明に係る焼結体の製造方法は、金属酸窒化物と、シアナミドを含む焼結助剤とが互いに接触された状態で、窒素を含む雰囲気中で焼結することを特徴とする。 The method for producing a sintered body according to the present invention is characterized in that the metal oxynitride and the sintering aid containing cyanamide are sintered in an atmosphere containing nitrogen while being in contact with each other.
　本発明に係る焼結体の製造方法では、好ましくは、前記シアナミドの融点は、前記金属酸窒化物の窒素脱離温度よりも低い。この場合には、窒素がより一層脱離し難いため、一層窒素含有量の多い焼結体をより確実に提供することができる。 In the method for producing a sintered body according to the present invention, preferably, the melting point of the cyanamide is lower than the nitrogen desorption temperature of the metal oxynitride. In this case, since nitrogen is more difficult to desorb, a sintered body with a higher nitrogen content can be provided more reliably.
　前記シアナミドとしては、好ましくは、ＢａＣＮ２が用いられる。この場合には、窒素含有量の多い焼結体をより一層確実に提供することができる。 As the cyanamide, BaCN 2 is preferably used. In this case, a sintered body with a high nitrogen content can be provided more reliably.
　本発明の焼結体の製造方法では、好ましくは、前記金属酸窒化物は、前記シアナミドが融解した液相に溶解する材料である。この場合には、窒素含有量の多い焼結体をより確実に提供することができる。 In the method for producing a sintered body according to the present invention, preferably, the metal oxynitride is a material that dissolves in a liquid phase in which the cyanamide is melted. In this case, a sintered body with a high nitrogen content can be provided more reliably.
　本発明に係る焼結体の製造方法のさらに他の特定の局面では、前記金属酸窒化物は、ＢａＴａＯ２Ｎ及びＳｒＴａＯ２Ｎから選択される一種である。 In still another specific aspect of the method for producing a sintered body according to the present invention, the metal oxynitride is a kind selected from BaTaO 2 N and SrTaO 2 N.
　本発明に係る焼結体の製造方法の他の特定の局面では、前記焼結に際し、８８０℃以上、９５０℃以下の温度で加熱する。この場合には、窒素が脱離し難く、窒素含有量の多い焼結体を得ることができる。 In another specific aspect of the method for producing a sintered body according to the present invention, the sintering is performed at a temperature of 880 ° C. or higher and 950 ° C. or lower. In this case, it is difficult to desorb nitrogen, and a sintered body with a high nitrogen content can be obtained.
　本発明に係る焼結体の製造方法のさらに他の特定の局面では、前記焼結助剤は、前記金属酸窒化物１００重量％に対し、３重量％以上、５０重量％以下の割合で用いられる。この場合には、窒素含有量の高い焼結体をより一層確実に提供することができる。 In still another specific aspect of the method for producing a sintered body according to the present invention, the sintering aid is used in a proportion of 3 wt% or more and 50 wt% or less with respect to 100 wt% of the metal oxynitride. It is done. In this case, a sintered body having a high nitrogen content can be provided more reliably.
　本発明に係る焼結体の製造方法のさらに他の特定の局面では、前記焼結助剤は、粉体状又は粒子状であり、前記金属酸窒化物に混合された状態で、前記焼結が行われる。 In still another specific aspect of the method for producing a sintered body according to the present invention, the sintering aid is in the form of powder or particles and is mixed with the metal oxynitride in the sintered state. Is done.
　本発明に係る焼結体及びその製造方法によれば、従来の一部のみが窒化された金属酸窒化物からなる焼結体に比べて、窒素含有量が豊富な焼結体を提供することができる。従って、誘電特性に優れた誘電体組成物を本発明により提供することができる。 According to the sintered body and the method for producing the same according to the present invention, it is possible to provide a sintered body rich in nitrogen as compared to a conventional sintered body made of a metal oxynitride that is partially nitrided. Can do. Therefore, a dielectric composition having excellent dielectric characteristics can be provided by the present invention.
　また、上記誘電体組成物を用いて静電容量の高いキャパシタを提供することができる。さらには、本発明に係る焼結体を用いて、光触媒組成物、光電変換素子及びガスセンサなどを提供することが可能となる。 Also, a capacitor having a high capacitance can be provided using the dielectric composition. Furthermore, it becomes possible to provide a photocatalyst composition, a photoelectric conversion element, a gas sensor, and the like using the sintered body according to the present invention.
図１は、本発明の実施例１で用いられるＢａＣＮ２のＸＲＤパターンを示す図である。FIG. 1 is a diagram showing an XRD pattern of BaCN 2 used in Example 1 of the present invention. 図２は、ＢａＣＮ２の添加割合が、金属酸窒化物１００重量％に対し、３０重量％である組成を用いた焼結体のＸＲＤパターンを示す図である。Figure 2 is a proportion of the added bit BACn 2 is replaced by a metal oxynitride 100 wt% with respect to a drawing showing an XRD pattern of the sintered body using a composition of 30 wt%. 図３は、本発明の実施形態で得られた焼結体の３００倍のＳＥＭ写真である。FIG. 3 is a 300 times SEM photograph of the sintered body obtained in the embodiment of the present invention. 図４は、本発明の実施形態で得られた焼結体の１００００倍のＳＥＭ写真である。FIG. 4 is a 10,000 times SEM photograph of the sintered body obtained in the embodiment of the present invention. 図５は、実施例１で得られた焼結体のＳＴＥＭ写真である。FIG. 5 is a STEM photograph of the sintered body obtained in Example 1. 図６は、実施例１で得られた焼結体の他の部分のＳＴＥＭ写真である。6 is a STEM photograph of another part of the sintered body obtained in Example 1. FIG. 図７は、図５に示したＳＴＥＭ写真を拡大した写真と、この写真で表された部分のある部分の電子回折図形及び他の部分の電子回折図形を示す写真である。FIG. 7 is an enlarged photograph of the STEM photograph shown in FIG. 5, and a photograph showing an electron diffraction pattern of a part having a portion represented by this photograph and an electron diffraction pattern of another part. 図８は、実施例１で得た焼結体のＴＥＭ－ＥＤＸスペクトル分析において観察した部分のＴＥＭ写真である。FIG. 8 is a TEM photograph of a portion observed in the TEM-EDX spectrum analysis of the sintered body obtained in Example 1. 図９は、図８に示した写真の一部の部分におけるＴＥＭ－ＥＤＸスペクトルを示す図である。FIG. 9 is a diagram showing a TEM-EDX spectrum in a part of the photograph shown in FIG. 図１０は、図８に示した写真の他の部分におけるＴＥＭ－ＥＤＸスペクトルを示す図である。FIG. 10 is a diagram showing a TEM-EDX spectrum in another part of the photograph shown in FIG. 図１１は、実施例１で得られた焼結体のＴＥＭ－ＥＤＸ元素マッピング分析箇所のＴＥＭ写真である。FIG. 11 is a TEM photograph of a TEM-EDX element mapping analysis site of the sintered body obtained in Example 1. 図１２は、図１１に示した写真の部分の炭素（Ｃ）原子のＴＥＭ－ＥＤＸ元素マッピングを示す図である。FIG. 12 is a diagram showing a TEM-EDX element mapping of carbon (C) atoms in the part of the photograph shown in FIG. 図１３は、図１１に示した写真の部分の窒素（Ｎ）原子のＴＥＭ－ＥＤＸ元素マッピングを示す図である。FIG. 13 is a diagram showing a TEM-EDX element mapping of nitrogen (N) atoms in the part of the photograph shown in FIG. 図１４は、図１１に示した写真の部分のストロンチウム（Ｓｒ）原子のＴＥＭ－ＥＤＸ元素マッピングを示す図である。FIG. 14 is a diagram showing a TEM-EDX element mapping of strontium (Sr) atoms in the part of the photograph shown in FIG. 図１５は、図１１に示した写真の部分のバリウム（Ｂａ）原子のＴＥＭ－ＥＤＸ元素マッピングを示す図である。FIG. 15 is a diagram showing a TEM-EDX element mapping of barium (Ba) atoms in the part of the photograph shown in FIG. 図１６は、図１１に示した写真の部分のタンタル（Ｔａ）原子のＴＥＭ－ＥＤＸ元素マッピングを示す図である。FIG. 16 is a diagram showing a TEM-EDX element mapping of tantalum (Ta) atoms in the part of the photograph shown in FIG. 図１７は、実施例１で得られた焼結体の他の部分におけるＴＥＭ－ＥＤＸ元素マッピング分析箇所のＴＥＭ写真である。FIG. 17 is a TEM photograph of a TEM-EDX element mapping analysis site in another part of the sintered body obtained in Example 1. 図１８は、図１７に示した写真の部分の炭素（Ｃ）原子のＴＥＭ－ＥＤＸ元素マッピングを示す図である。18 is a diagram showing a TEM-EDX element mapping of carbon (C) atoms in the part of the photograph shown in FIG. 図１９は、図１７に示した写真の部分の窒素（Ｎ）原子のＴＥＭ－ＥＤＸ元素マッピングを示す図である。FIG. 19 is a diagram showing a TEM-EDX element mapping of nitrogen (N) atoms in the part of the photograph shown in FIG. 図２０は、図１７に示した写真の部分のストロンチウム（Ｓｒ）原子のＴＥＭ－ＥＤＸ元素マッピングを示す図である。FIG. 20 is a diagram showing a TEM-EDX element mapping of strontium (Sr) atoms in the part of the photograph shown in FIG. 図２１は、図１７に示した写真の部分のバリウム（Ｂａ）原子のＴＥＭ－ＥＤＸ元素マッピングを示す図である。FIG. 21 is a diagram showing a TEM-EDX element mapping of barium (Ba) atoms in the part of the photograph shown in FIG. 図２２は、図１７に示した写真の部分のタンタル（Ｔａ）原子のＴＥＭ－ＥＤＸ元素マッピングを示す図である。FIG. 22 is a diagram showing a TEM-EDX element mapping of tantalum (Ta) atoms in the part of the photograph shown in FIG. 図２３（ａ）及び図２３（ｂ）は、エッチングされた後の実施例１の焼結体の１００００倍及び５００００倍の倍率の各ＳＥＭ写真である。FIG. 23A and FIG. 23B are SEM photographs of magnifications of 10000 times and 50000 times of the sintered body of Example 1 after being etched. 図２４は、実施例１で得られた焼結体の複素インピーダンス特性を示す図である。FIG. 24 is a diagram showing the complex impedance characteristics of the sintered body obtained in Example 1. 図２５は、実施例１で得られた焼結体の誘電物性を示す図である。FIG. 25 is a diagram showing the dielectric properties of the sintered body obtained in Example 1. 図２６は、実施例１で得られた焼結体の誘電物性の温度特性を示す図である。FIG. 26 is a diagram showing temperature characteristics of dielectric properties of the sintered body obtained in Example 1. 図２７（ａ）～図２７（ｃ）は、実施例３で得られた焼結体の２０００倍、５０００倍、及び１００００倍の倍率のＳＥＭ写真である。27 (a) to 27 (c) are SEM photographs of magnifications of 2000 times, 5000 times, and 10000 times that of the sintered body obtained in Example 3. FIG. 図２８（ａ）及び図２８（ｂ）は、実施例３で得られた焼結体のＳＴＥＭ写真である。28A and 28B are STEM photographs of the sintered body obtained in Example 3. FIG. 図２９（ａ）～図２９（ｃ）は、実施例３で得られた焼結体のＳＴＥＭ写真である。29 (a) to 29 (c) are STEM photographs of the sintered body obtained in Example 3. FIG. 図３０は、図２９（ａ）に示したＳＴＥＭ写真の一部におけるＳＴＥＭ－ＥＤＸスペクトルを示す図である。FIG. 30 is a diagram showing a STEM-EDX spectrum in a part of the STEM photograph shown in FIG. 図３１は、図２９（ａ）に示したＳＴＥＭ写真の他の一部におけるＳＴＥＭ－ＥＤＸスペクトルを示す図である。FIG. 31 is a diagram showing a STEM-EDX spectrum in another part of the STEM photograph shown in FIG. 図３２は、実施例３で得られた焼結体における各部分のＸＲＤパターンを示す図である。また、図内のＳｒ／Ｂａ／Ｔａの右側の数字は、焼結体の各部分のＸＲＦ分析による、Ｓｒ、Ｂａ、Ｔａの各原子の個数比率（ａｔ％）である。32 is a view showing XRD patterns of respective portions in the sintered body obtained in Example 3. FIG. Further, the numbers on the right side of Sr / Ba / Ta in the figure are the number ratios (at%) of the respective atoms of Sr, Ba, and Ta by XRF analysis of each part of the sintered body. 図３３は、実施例３で得られた焼結体の複素インピーダンス特性を示す図である。FIG. 33 is a diagram showing the complex impedance characteristics of the sintered body obtained in Example 3. 図３４は、実施例３で得られた誘電物性を示す図である。FIG. 34 is a diagram showing the dielectric properties obtained in Example 3. 図３５は、実施例３で得られた焼結体の比誘電率の温度特性を示す図である。FIG. 35 is a graph showing temperature characteristics of relative permittivity of the sintered body obtained in Example 3. 図３６は、実施例３で得られた焼結体の誘電損失（ｔａｎδ）の温度特性を示す図である。FIG. 36 is a graph showing the temperature characteristics of dielectric loss (tan δ) of the sintered body obtained in Example 3. 図３７は、ＢａＴａＯ２Ｎ、ＳｒＴａＯ２Ｎ及び実施例４で得た硝酸で洗浄されたＳｒ１－ｘＢａｘＴａＯ２ＮのＸＲＤパターンを示す図である。FIG. 37 is a diagram showing XRD patterns of BaTaO 2 N, SrTaO 2 N, and Sr 1-x Ba x TaO 2 N washed with nitric acid obtained in Example 4. 図３８（ａ）～図３８（ｃ）は、実施例４で得た硝酸で洗浄されたＳｒ１－ｘＢａｘＴａＯ２Ｎ粒子のＳＥＭ－ＥＤＸ元素マッピングを説明するための各図である。FIGS. 38A to 38C are diagrams for explaining SEM-EDX element mapping of Sr 1-x Ba x TaO 2 N particles washed with nitric acid obtained in Example 4. FIG. 図３９（ａ）～図３９（ｃ）は、実施例４で得た硝酸で洗浄されたＳｒ１－ｘＢａｘＴａＯ２Ｎ粒子のＳＥＭ－ＥＤＸ元素マッピングを説明するための各図である。FIGS. 39A to 39C are diagrams for explaining SEM-EDX element mapping of the Sr 1-x Ba x TaO 2 N particles washed with nitric acid obtained in Example 4. FIG. 図４０（ａ）及び図４０（ｂ）は、実施例４で得た硝酸で洗浄されたＳｒ１－ｘＢａｘＴａＯ２Ｎ粒子の２００００倍及び５００００倍の各ＳＥＭ写真である。40 (a) and 40 (b) are SEM photographs of 20000 times and 50000 times of Sr 1-x Ba x TaO 2 N particles washed with nitric acid obtained in Example 4, respectively. 図４１（ａ）及び図４１（ｂ）は、実施例４で得た硝酸で洗浄されたＳｒ１－ｘＢａｘＴａＯ２Ｎ粒子の２００００倍及び５００００倍の各ＳＥＭ写真である。41A and 41B are SEM photographs of 20000 times and 50000 times of Sr 1-x Ba x TaO 2 N particles washed with nitric acid obtained in Example 4, respectively. 図４２は、実施例５で得られた焼結体及び焼結体を蒸留水に浸漬させた後乾燥させて得られた粉体のＸＲＤパターンを示す図である。FIG. 42 is a diagram showing an XRD pattern of a powder obtained by immersing the sintered body obtained in Example 5 and the sintered body in distilled water and then drying. 図４３（ａ）及び図４３（ｂ）は、実施例５で得られた焼結体の５００倍及び１００００倍の各ＳＥＭ写真である。43 (a) and 43 (b) are SEM photographs of 500 times and 10,000 times the sintered body obtained in Example 5, respectively. 図４４（ａ）及び図４４（ｂ）は、実施例５において焼結体を蒸留水に浸漬させた後乾燥させて得られた粉体の５００倍及び１００００倍の各ＳＥＭ写真である。44 (a) and 44 (b) are SEM photographs of 500 times and 10,000 times the powder obtained by immersing the sintered body in distilled water and drying it in Example 5. FIG. 図４５は、実施例５で得られた焼結体の複素インピーダンス特性を示す図である。FIG. 45 is a diagram showing complex impedance characteristics of the sintered body obtained in Example 5. 図４６は、実施例５で得られた誘電物性を示す図である。FIG. 46 is a diagram showing the dielectric properties obtained in Example 5. 図４７は、実施例５で得られた焼結体のＳＴＥＭ写真である。FIG. 47 is a STEM photograph of the sintered body obtained in Example 5. 図４８は、実施例５で得られた焼結体のＳＴＥＭ写真の部分におけるＳＴＥＭ－ＥＤＸ元素マッピングを示す図である。FIG. 48 is a diagram showing STEM-EDX element mapping in the STEM photograph of the sintered body obtained in Example 5. 図４９は、実施例６で得られた焼結体のＸＲＤパターンを示す図である。FIG. 49 is a view showing an XRD pattern of the sintered body obtained in Example 6. FIG. 図５０（ａ）～図５０（ｃ）は、実施例６で得られた焼結体の５００倍、１０００倍及び１５０００倍の各ＳＥＭ写真である。50 (a) to 50 (c) are SEM photographs of 500 times, 1000 times and 15000 times that of the sintered body obtained in Example 6. FIG. 図５１は、実施例６で得られた焼結体の複素インピーダンス特性を示す図である。FIG. 51 is a diagram showing the complex impedance characteristics of the sintered body obtained in Example 6. 図５２は、実施例６で得られた誘電物性を示す図である。FIG. 52 is a view showing dielectric properties obtained in Example 6. 図５３は、実施例６で得られた焼結体のＴＥＭ写真および、ＳＴＥＭ写真中の結晶粒子と考えられる箇所の電子線回折像である。FIG. 53 is a TEM photograph of the sintered body obtained in Example 6, and an electron diffraction pattern of a portion considered to be a crystal particle in the STEM photograph. 図５４は、図５３に示したＴＥＭ写真の一部におけるＳＴＥＭ－ＥＤＸスペクトルを示す図である。FIG. 54 is a diagram showing a STEM-EDX spectrum in a part of the TEM photograph shown in FIG. 図５５は、図５３に示したＴＥＭ写真の他の一部におけるＳＴＥＭ－ＥＤＸスペクトルを示す図である。FIG. 55 is a view showing a STEM-EDX spectrum in another part of the TEM photograph shown in FIG. 図５６は、実施例７で得られた焼結体のＸＲＤパターンである。FIG. 56 is an XRD pattern of the sintered body obtained in Example 7.
　以下、図面を参照しつつ、本発明の具体的な実施形態を説明することにより、本発明を明らかにする。 Hereinafter, the present invention will be clarified by describing specific embodiments of the present invention with reference to the drawings.
　なお、本明細書に記載の各実施形態は、例示的なものであり、異なる実施形態間において、構成の部分的な置換または組み合わせが可能であることを指摘しておく。 It should be pointed out that each embodiment described in this specification is an example, and a partial replacement or combination of configurations is possible between different embodiments.
　本願発明者らは、前述した課題を鋭意検討した結果、金属酸窒化物と、シアナミドを含む焼結助剤とを用いて窒素を含む雰囲気中で焼結すれば、十分に窒化されている焼結体が得られることを見出し、本発明をなすに至った。そして、本発明に係る焼結体は、金属酸窒化物を含む複数の結晶粒と、非晶質との集合体を含むことを特徴とする。 As a result of intensive studies on the above-mentioned problems, the inventors of the present application have found that if the sintering is carried out in an atmosphere containing nitrogen using a metal oxynitride and a sintering aid containing cyanamide, the sintered material is sufficiently nitrided. The inventors found that a ligation was obtained and reached the present invention. The sintered body according to the present invention includes an aggregate of a plurality of crystal grains including metal oxynitride and amorphous.
　以下、本発明の詳細を説明する。 Hereinafter, the details of the present invention will be described.
　本発明に係る焼結体は、上記の通り、複数の結晶粒と、非晶質との集合体とを含む。この複数の結晶粒における金属酸窒化物としては、特に限定されないが、さまざまな金属の酸窒化物を用いることができる。金属として、アルカリ土類金属や希土類金属が好適に用いられる。アルカリ土類金属や希土類金属を用いることにより、窒素含有量が高い焼結体を容易に得ることができる。アルカリ土類金属としては、ＢａまたはＳｒの少なくとも一方が好適に用いられる。また、希土類金属としてはＬａが好適に用いられる。ＢａやＳｒ、Ｌａを用いた場合、より一層窒素含有量の高い焼結体を確実に得ることができる。上記の通り、金属酸窒化物を含む複数の結晶粒は、結晶性である。本発明に係る焼結体は、この結晶性の複数の結晶粒と、非晶質の集合体を含む。 As described above, the sintered body according to the present invention includes a plurality of crystal grains and an aggregate of amorphous. The metal oxynitride in the plurality of crystal grains is not particularly limited, but various metal oxynitrides can be used. As the metal, an alkaline earth metal or a rare earth metal is preferably used. By using an alkaline earth metal or a rare earth metal, a sintered body having a high nitrogen content can be easily obtained. As the alkaline earth metal, at least one of Ba and Sr is preferably used. As the rare earth metal, La is preferably used. When Ba, Sr, or La is used, a sintered body with a still higher nitrogen content can be obtained with certainty. As described above, the plurality of crystal grains containing the metal oxynitride are crystalline. The sintered body according to the present invention includes the plurality of crystalline grains and an amorphous aggregate.
　上記非晶質は、結晶性でない適宜の材料からなる。好ましくは、上記非晶質は、結晶粒間の界面に存在している。また、複数の結晶粒は、好ましくは多結晶からなる。そして、上記非晶質はこの多結晶の結晶粒間に存在していることが望ましい。より具体的には、上記非晶質は上記多結晶の結晶粒界に沿って存在していることが望ましい。 The amorphous material is made of an appropriate material that is not crystalline. Preferably, the amorphous is present at an interface between crystal grains. The plurality of crystal grains are preferably made of polycrystal. The amorphous material is preferably present between the polycrystalline grains. More specifically, the amorphous material is desirably present along the polycrystalline grain boundary.
　また、非晶質を構成する材料は特に限定されないが、好ましくは、炭素を含み、より好ましくは、炭素と窒素とを含む。 The material constituting the amorphous material is not particularly limited, but preferably includes carbon, and more preferably includes carbon and nitrogen.
　さらに非晶質は、上述した金属酸窒化物を構成している金属元素と同種の元素を少なくとも１つ含んでいてもよい。その場合には、上述した金属酸窒化物が一部溶解し、再析出を生じることにより焼結が進展したと考えることができ、ゆえに非晶質部分は金属酸窒化物を焼結させるための助剤として働いていると考えることができる。 Further, the amorphous may contain at least one element of the same kind as the metal element constituting the metal oxynitride described above. In that case, it can be considered that the above-described metal oxynitride is partially dissolved and re-precipitation causes sintering to progress, and therefore the amorphous portion is used to sinter the metal oxynitride. You can think of it as an assistant.
　本発明においては、集合体の緻密性は、６５％以上であることが好ましい。ここで、緻密性の評価は、後述の実施例で説明するように、画像解析を利用して求められる。緻密性が６５％以上であれば、焼結体の緻密性が高いことが好ましい物性を活用した応用に用いることができる。該応用としては、例えば、上記焼結体を誘電体組成物に用いることが挙げられる。より好ましくは、集合体の少なくとも一部の緻密性が８０％以上である。 In the present invention, the denseness of the aggregate is preferably 65% or more. Here, the evaluation of the denseness is obtained by using image analysis, as will be described in Examples described later. If the denseness is 65% or more, it can be used for applications utilizing physical properties where it is preferable that the sintered body has high denseness. As the application, for example, the above-mentioned sintered body is used for a dielectric composition. More preferably, the denseness of at least a part of the aggregate is 80% or more.
　また、上記焼結体においては、結晶粒の円相当径の平均値は、好ましくは、０．１８μｍ以上である。その場合には、結晶粒は焼結体の原料である酸窒化物粒子が互いに結合・成長していると考えることができる。また、上記結晶粒の円相当径の平均値は、４．０μｍ以下であることが望ましい。上記円相当径の平均値は、粒子の形状や大きさを判別できる倍率で取得した画像（例えば倍率３万倍の走査型電子顕微鏡による観察像)に対して画像解析ソフト「Ａ像くん」（旭化成エンジニアリング株式会社製）を用いることにより求めることができる。 Further, in the sintered body, the average value of the equivalent circle diameters of the crystal grains is preferably 0.18 μm or more. In that case, it can be considered that the crystal grains are bonded and grown with the oxynitride particles as the raw material of the sintered body. The average value of the equivalent circle diameter of the crystal grains is preferably 4.0 μm or less. The average value of the equivalent circle diameter is calculated based on image analysis software “A Image-kun” (for example, an image observed with a scanning electron microscope with a magnification of 30,000 times) obtained at a magnification that can determine the shape and size of particles. Asahi Kasei Engineering Co., Ltd. can be used.
　上記「Ａ像くん」を用いた円相当径の平均値の解析方法を述べる。 The analysis method of the average value of equivalent circle diameter using the above "A image-kun" will be described.
　まず、走査型電子顕微鏡を用いて、個々の粒子の形状が判別できる程度の倍率の画像を取得した。このときの倍率としては、例えば５０００倍や１００００倍、あるいは３００００倍などが用いられる。次に、粒子の形状が目立つように明るさ、コントラストを調節した。２値化処理を行い、粒子部分のみを抽出した。 First, using a scanning electron microscope, an image having a magnification enough to distinguish the shape of each particle was obtained. As the magnification at this time, for example, 5000 times, 10,000 times, or 30000 times are used. Next, brightness and contrast were adjusted so that the shape of the particles was conspicuous. A binarization process was performed to extract only the particle portion.
　なお、上記「Ａ像くん」の２値化処理による粒子抽出では完全でない場合には手動で補った。 In addition, when the particle extraction by the binarization process of “A image-kun” is not complete, it was manually compensated.
　粒子以外の箇所、すなわち焼結体における非晶質部分や、空隙部分を抽出した場合は、これを削除した。 ∙ When a part other than particles, that is, an amorphous part or a void part in the sintered body was extracted, this was deleted.
　画像処理ソフトの「粒子解析」で粒子の個数、面積、円相当径を測定した。 The number, area, and equivalent circle diameter of particles were measured by “particle analysis” of image processing software.
　なお、上記結晶粒は、ペロブスカイト構造を含む。 Note that the crystal grains include a perovskite structure.
　本発明に係る焼結体は、比誘電率が高い。従って、本発明の焼結体は、誘電体組成物に好適に用いられる。 The sintered body according to the present invention has a high relative dielectric constant. Therefore, the sintered body of the present invention is suitably used for a dielectric composition.
　上記のように、本発明に係る焼結体が誘電体としての特性に優れていることは、焼結体中に、酸素と窒素が十分に含有されており、酸素あるいは窒素の格子欠陥が十分に少ないため、絶縁性が高められていることによると考えられる。後述の実施例で説明するように、本発明で得られた焼結体は、一般的な酸窒化物粉体とほぼ同様に、橙色～赤色を示している。従って、窒素の脱離があまり生じておらず、窒素含有量の多い焼結体の得られていることがわかる。 As described above, the fact that the sintered body according to the present invention is excellent in the characteristics as a dielectric is that oxygen and nitrogen are sufficiently contained in the sintered body, and lattice defects of oxygen or nitrogen are sufficient. Therefore, it is considered that the insulating property is enhanced. As will be described in the examples described later, the sintered body obtained in the present invention exhibits orange to red in substantially the same manner as general oxynitride powder. Therefore, it can be understood that a sintered body having a high nitrogen content is obtained with little nitrogen desorption.
　橙色～赤色の色調を示していることは、バンドギャップエネルギーが、可視光の領域にあることを示している。従って、本発明に係る焼結体及びその構成粒子は、光触媒組成物、光電変換素子などに好適に用いることができる。また、窒素が表面に存在するため、従来の酸化物センサでは測定できないガスを測定し得るガスセンサをも提供することが可能となる。 The orange to red color tone indicates that the band gap energy is in the visible light region. Therefore, the sintered body and its constituent particles according to the present invention can be suitably used for a photocatalyst composition, a photoelectric conversion element and the like. Further, since nitrogen is present on the surface, it is possible to provide a gas sensor that can measure a gas that cannot be measured by a conventional oxide sensor.
　本発明に係る焼結体の製造方法では、金属酸窒化物と、シアナミドを含む焼結助剤とを互いに接触させた状態で、窒素を含む雰囲気中で焼結する。このシアナミドを含む焼結助剤を用い、かつ窒素を含む雰囲気中で加熱して焼結することにより、窒素含有量の多い焼結体を得ることができる。 In the method for producing a sintered body according to the present invention, the metal oxynitride and the sintering aid containing cyanamide are sintered in an atmosphere containing nitrogen while being in contact with each other. By using this sintering aid containing cyanamide and sintering in an atmosphere containing nitrogen, a sintered body having a high nitrogen content can be obtained.
　上記シアナミドの融点は、上記金属酸窒化物の窒素脱離温度よりも低いことが好ましい。それによって、窒素の脱離が焼結に際してより一層生じ難い。上記シアナミドは特に限定されないが、好ましくは、ＢａＣＮ２、ＳｒＣＮ２、ＣａＣＮ２などを用いることができ、より好ましくは、ＢａＣＮ２が用いられる。 The melting point of the cyanamide is preferably lower than the nitrogen desorption temperature of the metal oxynitride. Thereby, nitrogen desorption is less likely to occur during sintering. The cyanamide is not particularly limited, preferably, can be used as the BaCN 2, SrCN 2, CaCN 2 , more preferably, bit BACn 2 is used.
　上記ＢａＣＮ２は、焼結助剤として用いられているものであり、得られた焼結体では、ＢａＣＮ２の結晶構造は見られない。すなわち、金属酸窒化物からなる結晶粒間に、非晶質部分が存在している。 The BaCN 2 is used as a sintering aid, and the crystal structure of BaCN 2 is not observed in the obtained sintered body. That is, an amorphous part exists between crystal grains made of metal oxynitride.
　本発明の製造方法において、金属酸窒化物は、シアナミドが融解した液相に溶解する材料であることが好ましい。それによって、窒素含有量の多い焼結体をより確実に提供することができる。このような金属酸窒化物としては、特に限定されないが、例えば、ＢａＴａＯ２ＮやＳｒＴａＯ２Ｎなどが用いられる。 In the production method of the present invention, the metal oxynitride is preferably a material that dissolves in a liquid phase in which cyanamide is melted. Thereby, a sintered body with a high nitrogen content can be provided more reliably. Such metal oxynitride is not particularly limited, for example, BaTaO 2 N and SrTaO 2 N is used.
　焼結助剤として、ＢａＣＮ２を用い、金属酸窒化物としてＳｒＴａＯ２Ｎを用いた場合の製造方法の一実施態様について説明する。 An embodiment of the production method in the case where BaCN 2 is used as the sintering aid and SrTaO 2 N is used as the metal oxynitride will be described.
　ＢａＣＮ２の融点は９００℃付近である。他方、ＳｒＴａＯ２Ｎの窒素脱離を伴う重量変化開始温度は１０００℃付近である。従って、ＳｒＴａＯ２Ｎの窒素の脱離が生じ難い、９００℃付近の温度で、ＳｒＴａＯ２Ｎの周囲に存在するＢａＣＮ２が液相に変化する。よって、ＳｒＴａＯ２Ｎ粒子が、液相のＢａＣＮ２に溶解し、再析出する現象を繰り返すこととなる。すなわち、液相焼結により、ＳｒＴａＯ２Ｎが焼結されることとなる。ＳｒＴａＯ２Ｎ粒子が、溶解及び再析出現象を繰り返すことにより、互いに結着し、粒成長が進む。その結果、Ｓｒ１－ｘＢａｘＴａＯ２Ｎの焼結体を得ることができる。 The melting point of BaCN 2 is around 900 ° C. On the other hand, the weight change start temperature accompanied by nitrogen desorption of SrTaO 2 N is around 1000 ° C. Therefore, SrTaO 2 N hardly desorption occurs nitrogen, at temperatures around 900 ° C., bit BACn 2 present around the SrTaO 2 N is changed to a liquid phase. Therefore, the phenomenon that SrTaO 2 N particles are dissolved in the liquid phase BaCN 2 and re-deposited is repeated. That is, SrTaO 2 N is sintered by liquid phase sintering. The SrTaO 2 N particles are bonded to each other by repeating the dissolution and reprecipitation phenomenon, and the grain growth proceeds. As a result, a sintered body of Sr 1-x Ba x TaO 2 N can be obtained.
　なお、従来、ＳｒＴａＯ２Ｎの焼結には、１４００℃以上の高温を必要としていた。これに対して、本発明の製造方法では、８００℃～９００℃程度の低温で焼成を行うことができる。そのため、焼成に際しての窒素の脱離が生じ難い。その結果、窒素含有量の高められた焼結体を得ることが可能とされている。 Conventionally, SrTaO 2 N sintering has required a high temperature of 1400 ° C. or higher. On the other hand, in the production method of the present invention, firing can be performed at a low temperature of about 800 ° C. to 900 ° C. Therefore, nitrogen desorption is unlikely to occur during firing. As a result, it is possible to obtain a sintered body with an increased nitrogen content.
　上記のように、ＳｒＴａＯ２Ｎからの窒素の脱離温度は１０００℃付近である。従って、本発明の製造方法では、１０００℃よりも低い温度で焼成することが好ましい。より好ましくは、本発明に係る焼結体の製造方法では、焼成に際しては、金属酸窒化物とシアナミドを含む焼結助剤とが互いに接触された状態で、８８０℃以上、９５０℃以下の温度で加熱することが好ましい。この温度範囲内であれば、窒素の脱離がより一層生じ難い。 As described above, the desorption temperature of nitrogen from SrTaO 2 N is around 1000 ° C. Therefore, in the production method of the present invention, firing is preferably performed at a temperature lower than 1000 ° C. More preferably, in the method for producing a sintered body according to the present invention, at the time of firing, the metal oxynitride and the sintering aid containing cyanamide are in contact with each other at a temperature of 880 ° C. or higher and 950 ° C. or lower. It is preferable to heat with. Within this temperature range, nitrogen desorption is less likely to occur.
　上記焼結に際し、金属酸窒化物とシアナミドを含む焼結助剤とを互いに接触させる態様については、特に限定されない。金属酸窒化物とシアナミドを含む焼結助剤とを混合してもよい。あるいは、金属酸窒化物上に、シアナミドを含む焼結助剤を載置してもよい。 In the above-described sintering, the aspect in which the metal oxynitride and the sintering aid containing cyanamide are brought into contact with each other is not particularly limited. A metal oxynitride and a sintering aid containing cyanamide may be mixed. Alternatively, a sintering aid containing cyanamide may be placed on the metal oxynitride.
　なお、本発明の焼結体の製造方法では、好ましくは、一回の焼成により焼結体を得る。この場合には、窒素の脱離がより一層生じ難い。 In the method for producing a sintered body of the present invention, preferably, the sintered body is obtained by a single firing. In this case, nitrogen desorption is less likely to occur.
　本発明の焼結体の製造方法において、窒素の脱離が生じ難いのは、上記のように、窒素が脱離する温度よりも低い温度で焼成すること、及び窒素雰囲気下で焼成することによる。 In the method for producing a sintered body according to the present invention, nitrogen is hardly desorbed by firing at a temperature lower than the temperature at which nitrogen is desorbed and by firing in a nitrogen atmosphere as described above. .
　好ましくは、焼結助剤は、粉体状または粒子状であることが望ましい。その場合には、金属酸窒化物を容易に混合することができ、混合状態で上記焼結を行うことができる。従って、窒素含有量の多い焼結体をより一層確実に得ることができる。 Preferably, the sintering aid is preferably in the form of powder or particles. In that case, the metal oxynitride can be easily mixed, and the sintering can be performed in a mixed state. Therefore, a sintered body with a high nitrogen content can be obtained more reliably.
　なお、上記焼結助剤の使用量は特に限定されないが、金属酸窒化物１００重量％に対し、３重量％以上の割合で用いることが望ましく、５重量％以上の割合で用いることがより望ましく、１０重量％以上の割合で用いることがさらに望ましい。また、上記焼結助剤の使用量としては、金属酸窒化物１００重量％に対し、５０重量％以下の割合で用いることが望ましい。上記範囲内であれば、窒素含有量の多い焼結体をより一層確実に得ることができる。 The amount of the sintering aid used is not particularly limited, but it is preferably 3% by weight or more, more preferably 5% by weight or more based on 100% by weight of the metal oxynitride. More preferably, it is used at a ratio of 10% by weight or more. Further, the amount of the sintering aid used is desirably 50% by weight or less based on 100% by weight of the metal oxynitride. If it is in the said range, a sintered compact with much nitrogen content can be obtained still more reliably.
　上記焼結体の製造方法では、焼結に際し、窒素雰囲気下で焼結を行うため、電気炉などを用い連続的に製造することができる。従来のアンモニアガスを用いた製造方法では、バッチ式製造方法を用いねばならなかった。これに対して、上記の通り、連続的な製造方法を用いることができるため、生産性を効果的に高めることができる。 In the method for producing a sintered body, since sintering is performed in a nitrogen atmosphere at the time of sintering, it can be continuously produced using an electric furnace or the like. In the conventional production method using ammonia gas, a batch production method has to be used. On the other hand, since a continuous manufacturing method can be used as above-mentioned, productivity can be improved effectively.
　本発明に係る焼結体からなる誘電体組成物は、好ましくは、３０℃～１５０℃の環境において、５ＭＨｚ～１００ＭＨｚの電場が印加された際の比誘電率が、１００以上、２００以下である。また、本発明に係る焼結体からなる誘電体組成物は、好ましくは、３０℃～１５０℃の温度範囲内での温度変化による、比誘電率の変化率が１０％以内である。 The dielectric composition comprising the sintered body according to the present invention preferably has a relative dielectric constant of 100 or more and 200 or less when an electric field of 5 MHz to 100 MHz is applied in an environment of 30 ° C. to 150 ° C. . In addition, the dielectric composition comprising the sintered body according to the present invention preferably has a change rate of a relative dielectric constant within 10% due to a temperature change within a temperature range of 30 ° C. to 150 ° C.
　従って、本発明に係る誘電体組成物は、例えばキャパシタに好適に用いることができる。 Therefore, the dielectric composition according to the present invention can be suitably used for a capacitor, for example.
　より好ましくは、金属酸窒化物の結晶粒と、非晶質との集合体は、１ＭＨｚの電場が印加された場合に、－５０℃～５０℃の温度範囲内での温度変化による、比誘電率の変化率が３％以内である。この場合には、温度変化による比誘電率の変化が小さいコンデンサを提供することができる。 More preferably, the aggregate of the metal oxynitride crystal grains and the amorphous material has a dielectric constant caused by a temperature change within a temperature range of −50 ° C. to 50 ° C. when an electric field of 1 MHz is applied. The rate of change of the rate is within 3%. In this case, it is possible to provide a capacitor having a small change in relative dielectric constant due to a temperature change.
　本発明に係るキャパシタの構造は特に限定されないが、本発明に係る誘電体組成物と、誘電体組成物を介して対向されている一対の電極とを備えるものであればよい。この場合、一対の電極の一方の電極が、誘電体組成物のある面に設けられ、誘電体組成物の他の面に他方の電極が設けられてもよい。あるいは、誘電体組成物の同一面において、ギャップを隔てて一対の電極が設けられていてもよい。 The structure of the capacitor according to the present invention is not particularly limited as long as it includes the dielectric composition according to the present invention and a pair of electrodes opposed via the dielectric composition. In this case, one electrode of the pair of electrodes may be provided on one surface of the dielectric composition, and the other electrode may be provided on the other surface of the dielectric composition. Alternatively, a pair of electrodes may be provided on the same surface of the dielectric composition with a gap therebetween.
　光触媒組成物では、バンドギャップエネルギーが可視光領域内、すなわち１．６５ｅＶ～３．２６ｅＶの領域にあることが好ましいとされている。利用できる太陽光のエネルギー幅が増加するため、光触媒特性を高め得るからである。本発明により得られた焼結体は、橙色～赤色の色調を示す。従って、バンドギャップエネルギーが可視光の領域にあると推測される。よって、本発明に係る焼結体は、光触媒組成物に好適に用いることができる。 In the photocatalyst composition, the band gap energy is preferably in the visible light region, that is, in the region of 1.65 eV to 3.26 eV. This is because the photocatalytic properties can be enhanced because the energy range of available sunlight increases. The sintered body obtained by the present invention exhibits a color tone of orange to red. Therefore, it is estimated that the band gap energy is in the visible light region. Therefore, the sintered body according to the present invention can be suitably used for the photocatalyst composition.
　また、太陽電池などの光電変換素子においても、光電変換材料は可視光領域にバンドギャップエネルギーを有することが望ましく、かつ不純物が少ないことが好ましい。従って、本発明の焼結体は、上記光電変換素子に好適に用いられ得る。 Also in a photoelectric conversion element such as a solar cell, it is desirable that the photoelectric conversion material has a band gap energy in the visible light region, and it is preferable that there are few impurities. Therefore, the sintered body of the present invention can be suitably used for the photoelectric conversion element.
　以下、具体的な実施例及び比較例を挙げることにより、本発明をより詳細に説明する。 Hereinafter, the present invention will be described in more detail by giving specific examples and comparative examples.
　（実施例１）
　従来の金属酸窒化物焼結体では、窒素が脱離し半導体化している。そのため、電気抵抗が低く、誘電体として用いることは困難であった。 Example 1
In the conventional metal oxynitride sintered body, nitrogen is desorbed and becomes a semiconductor. Therefore, electric resistance is low and it was difficult to use as a dielectric.
　これに対して、本発明で得られた焼結体は、窒素を多く含有しており、絶縁体すなわち誘電体としての特性を示す。よって、誘電体組成物に本発明の焼結体を好適に用いることができる。 On the other hand, the sintered body obtained in the present invention contains a large amount of nitrogen and exhibits characteristics as an insulator, that is, a dielectric. Therefore, the sintered body of the present invention can be suitably used for the dielectric composition.
　（１）ＳｒＴａＯ２Ｎの合成
　炭酸ストロンチウム（ＳｒＣＯ３）粉体と、炭酸ストロンチウム粉体に対し、１／２モル量の酸化タンタル（Ｔａ２Ｏ５）とをアセトン分散媒中で混合した。空気中で乾燥させたのち、電気炉を用いて、大気雰囲気下で１２００℃の温度で１２時間熱処理した。それによって、Ｓｒ２Ｔａ２Ｏ７粉体を得た。 (1) Synthesis of SrTaO 2 N Strontium carbonate (SrCO 3 ) powder and strontium carbonate powder were mixed with ½ molar amount of tantalum oxide (Ta 2 O 5 ) in an acetone dispersion medium. After drying in air, heat treatment was performed for 12 hours at a temperature of 1200 ° C. in an air atmosphere using an electric furnace. Thereby, Sr 2 Ta 2 O 7 powder was obtained.
　得られたＳｒ２Ｔａ２Ｏ７粉体を、酸化アルミニウム（Ａｌ２Ｏ３）からなるボート上に配置し、石英ガラス炉心管を有する管状炉内に設けた。炉心管内にアンモニアガスを１００ｍｌ／分の流量で流し、１０００℃で８０時間加熱し、ＳｒＴａＯ２Ｎ粉体を合成した。管状炉温度コントローラーによる昇温速度は５℃／分、降温速度は３℃／分とした。 The obtained Sr 2 Ta 2 O 7 powder was placed on a boat made of aluminum oxide (Al 2 O 3 ) and provided in a tubular furnace having a quartz glass furnace tube. Ammonia gas was allowed to flow through the furnace core tube at a flow rate of 100 ml / min and heated at 1000 ° C. for 80 hours to synthesize SrTaO 2 N powder. The temperature rising rate by the tubular furnace temperature controller was 5 ° C./min, and the temperature lowering rate was 3 ° C./min.
　得られたＳｒＴａＯ２Ｎ粉体を粉末Ｘ線回析（ＸＲＤ）装置を用い、結晶分析を行った。その結果、ＳｒＴａＯ２Ｎの無機結晶構造データと一致することを確認した。 The obtained SrTaO 2 N powder was subjected to crystal analysis using a powder X-ray diffraction (XRD) apparatus. As a result, it was confirmed that it coincided with the inorganic crystal structure data of SrTaO 2 N.
　走査型電子顕微鏡（ＳＥＭ）を用い、得られた粉体の一次粒径を測定した。その結果、粒径は４０ｎｍ～１５０ｎｍ程度であった。また、平均粒径は９０ｎｍであった。 The primary particle size of the obtained powder was measured using a scanning electron microscope (SEM). As a result, the particle size was about 40 nm to 150 nm. The average particle size was 90 nm.
　（２）ＢａＣＮ２粉体の合成
　炭酸バリウム（ＢａＣＯ３）を酸化アルミニウムからなるボート上に配置し、（１）で用いたのと同じ管状炉内に配置した。炉心管内にアンモニアを５０ｍｌ／分の流量で流し、９００℃の温度で１０時間加熱し、粉体を得た。昇温・降温速度は、５℃／分とした。 (2) Synthesis of BaCN 2 powder Barium carbonate (BaCO 3 ) was placed on a boat made of aluminum oxide and placed in the same tubular furnace used in (1). Ammonia was flowed into the furnace tube at a flow rate of 50 ml / min and heated at a temperature of 900 ° C. for 10 hours to obtain a powder. The temperature increase / decrease rate was 5 ° C./min.
　得られた粉体をＸＲＤ装置を用いて結晶分析を行った。結果を図１に示す。得られた粉体の結晶相は、既存のＢａＣＮ２の粉末回折データファイル（ＪＣＰＤＳ　５１－５４２）とは異なった。従って、得られた粉体の結晶相は新規な結晶相であると考えられる。 The obtained powder was subjected to crystal analysis using an XRD apparatus. The results are shown in FIG. The crystal phase of the obtained powder was different from the existing BaCN 2 powder diffraction data file (JCPDS 51-542). Therefore, the crystal phase of the obtained powder is considered to be a novel crystal phase.
　また、得られた粉体の元素組成を、誘導結合プラズマ発光分光分析（ＩＣＰ－ＡＥＳ）を用いて分析した。その結果、Ｂａが７４重量％以上、７７重量％以下の割合で含まれていることがわかった。また、燃焼組成分析により、Ｃ及びＮがそれぞれ、６．５重量％及び１５．３重量％含まれていることがわかった。 In addition, the elemental composition of the obtained powder was analyzed using inductively coupled plasma emission spectroscopy (ICP-AES). As a result, it was found that Ba was contained at a ratio of 74 wt% or more and 77 wt% or less. Further, it was found by combustion composition analysis that C and N were contained by 6.5% by weight and 15.3% by weight, respectively.
　さらに、上記粉体を蒸留水中に投入したところ、アンモニア臭を伴いながら、ＢａＣＯ３相の沈殿を生成した。 Furthermore, when the powder was put into distilled water, a BaCO 3 phase precipitate was produced with an ammonia odor.
　これらの結果から、得られた粉体の組成は、ＢａＣＮ２と推定した。 These results, the composition of the obtained powder was estimated to be bit BACn 2.
　組成がＢａＣＮ２であると仮定し、上記粉体の結晶構造をＸＲＤにより調べた。推定された結晶構造に基づき、密度を求めた。その結果、理論密度は、４．５３ｇ／ｃｍ３と推定された。 Composition assuming a bit BACn 2, was examined by XRD crystal structure of the powder. The density was determined based on the estimated crystal structure. As a result, the theoretical density was estimated to be 4.53 g / cm 3 .
　（３）ＳｒＴａＯ２Ｎの液相焼結
　（１）で合成されたＳｒＴａＯ２Ｎ粉体と、（２）で合成されたＢａＣＮ２粉体とをメノウ鉢を用いて混合した。さらに、錠剤成型用金型を用い、混合物を、直径６ｍｍ、厚さ２ｍｍの円板の形状に成形した。ＳｒＴａＯ２Ｎ粉体とＢａＣＮ２粉体との混合比率は、ＳｒＴａＯ２Ｎ粉体１００重量部に対し、ＢａＣＮ２粉体が３０重量部とした。成形圧力は約４６ＭＰａとした。 (3) and SrTaO 2 N powders synthesized by SrTaO 2 N of liquid phase sintering (1) and mixed using an agate bowl and bit BACn 2 powder synthesized in (2). Further, using a tablet molding die, the mixture was molded into a disk shape having a diameter of 6 mm and a thickness of 2 mm. SrTaO 2 mixing ratio of N powder and bit BACn 2 powder, to SrTaO 2 N powder 100 parts by weight, bit BACn 2 powder was 30 parts by weight. The molding pressure was about 46 MPa.
　成形後、金型から成形体を取り出した。取り出された成形体を真空パックし、等方静水圧プレス機を用い、１５０ＭＰａで加圧した。加圧後に取り出された成形体を、（１）で合成されたＳｒＴａＯ２Ｎ粉体を埋め粉として用い、酸化アルミニウムのボート上に配置し、（１）及び（２）内で用いた管状炉内に配置した。炉心管に窒素ガスを５０ｍｌ／分の流量で流しつつ、９００℃の温度で３０時間加熱した。それによって、焼結体を得た。なお、昇温速度は５℃／分、降温速度は３℃／分とした。 After molding, the molded body was taken out from the mold. The removed molded body was vacuum packed and pressurized at 150 MPa using an isotropic isostatic press. The shaped body taken out after pressurization was placed on an aluminum oxide boat using the SrTaO 2 N powder synthesized in (1) as a filling powder, and the tubular furnace used in (1) and (2) Placed in. While flowing nitrogen gas through the furnace tube at a flow rate of 50 ml / min, heating was performed at a temperature of 900 ° C. for 30 hours. Thereby, a sintered body was obtained. The temperature rising rate was 5 ° C./min and the temperature lowering rate was 3 ° C./min.
　（４）焼結体の観察及び分析
　（３）で得られた加圧後の成形体の表面は橙色を呈していた。これに対して、（３）で得られた焼結体の表面は赤色に近い色となっていた。従って、焼結体のバンドギャップエネルギーは可視光領域内にあると推測される。 (4) Observation and Analysis of Sintered Body The surface of the pressed body obtained in (3) was orange. On the other hand, the surface of the sintered body obtained in (3) had a color close to red. Therefore, it is estimated that the band gap energy of the sintered body is in the visible light region.
　また、加圧された後の成形体の直径及び厚みは、直径が６ｍｍ及び厚みが２ｍｍであったのに対し、得られた焼結体の直径は５．４ｍｍ及び厚みは１．６ｍｍであった。上記成形体及び焼結体の体積及び重量から、得られた焼結体の密度は、成形体に比べて約４２％高くなっていることがわかった。 In addition, the diameter and thickness of the molded body after being pressed were 6 mm and 2 mm in diameter, whereas the diameter of the obtained sintered body was 5.4 mm and the thickness was 1.6 mm. It was. From the volume and weight of the molded body and the sintered body, it was found that the density of the obtained sintered body was about 42% higher than that of the molded body.
　焼結体の密度は約５．６ｇ／ｃｍ３であった。この焼結体の密度は、無機結晶構造データ（ＩＣＳＤ　９５３７３）に記載の計算密度である７．９７５ｇ／ｃｍ３の７０．２％であった。また、ＳｒＴａＯ２Ｎ粉体１００重量部と、ＢａＣＮ２粉体３０重量部との混合物の推定密度は、ＢａＣＮ２の密度４．５３ｇ／ｃｍ３とした場合、７．１８ｇ／ｃｍ３と推定される。従って、上記焼結体の密度は、この推定密度７．１８ｇ／ｃｍ３の７８％であった。 The density of the sintered body was about 5.6 g / cm 3 . The density of this sintered body was 70.2% of 7.975 g / cm 3 , which is the calculated density described in the inorganic crystal structure data (ICSD 95373). Further, the estimated density of the SrTaO 2 N powder 100 parts by weight of a mixture of bit BACn 2 powder 30 parts by weight, when the density of 4.53 g / cm 3 of bit BACn 2, is estimated to be 7.18 g / cm 3 The Therefore, the density of the sintered body was 78% of the estimated density of 7.18 g / cm 3 .
　得られた焼結体の表面から約０．２ｍｍの厚みの部分までを、耐水サンドペーパー（シリコンカーバイド砥粒、砥粒の粒径は２μｍ～３μｍ）を用いて乾式研磨した。しかる後、ＸＲＤ分析を行った。結果を図２に示す。 From the surface of the obtained sintered body to a portion having a thickness of about 0.2 mm was dry-polished using water-resistant sandpaper (silicon carbide abrasive grains, the grain diameter of the abrasive grains was 2 μm to 3 μm). Thereafter, XRD analysis was performed. The results are shown in FIG.
　図２に示されているように、回折ピーク位置は、ＳｒＴａＯ２Ｎに近い角度に分布している。従って、この焼結体の主な結晶相はペロブスカイト相であると推定される。 As shown in FIG. 2, the diffraction peak positions are distributed at an angle close to SrTaO 2 N. Therefore, it is presumed that the main crystal phase of this sintered body is a perovskite phase.
　また、水酸化バリウム水和物（Ｂａ（ＯＨ）２・Ｈ２Ｏ）と思われるピーク（ＩＣＳＤ　６３０１７）と、ＳｒＣＯ３の寄与によるピーク（ＩＣＳＤ　２７４４６）と思われる弱い回折ピークも存在している。 There are also a peak (ICSD 63017) that seems to be barium hydroxide hydrate (Ba (OH) 2 .H 2 O) and a weak diffraction peak that seems to be a peak due to the contribution of SrCO 3 (ICSD 27446). .
　他方、（２）で合成されていたＢａＣＮ２の回折ピークと同位置には、図２ではピークが見られない。ＢａＣＮ２の添加量は、ＳｒＴａＯ２Ｎの３０重量％であった。この添加量と比べると、Ｂａ（ＯＨ）２・Ｈ２Ｏの回折ピーク強度は著しく弱い。従って、ＢａＣＮ２に由来する物質は、得られた焼結体内で、非晶質として分布していると考えられる。 On the other hand, no peak is observed in FIG. 2 at the same position as the diffraction peak of BaCN 2 synthesized in (2). The amount of BaCN 2 added was 30% by weight of SrTaO 2 N. Compared to this added amount, the diffraction peak intensity of Ba (OH) 2 .H 2 O is remarkably weak. Therefore, it is considered that the substance derived from BaCN 2 is distributed as an amorphous substance in the obtained sintered body.
　得られた焼結体を破断し、破断面をＳＥＭを用いて観察した。このＳＥＭ写真を、図３及び図４に示す。図３に示す３００倍の観察写真では、粒子が緻密に存在している領域と、幅５０μｍ程度の空隙とが、規則性を有することなく分布している。また、図４に示す倍率１００００倍の観察写真において、緻密な部分を観察すると、幅１μｍ以上の比較的大きな空隙は見られない。 The obtained sintered body was fractured, and the fractured surface was observed using SEM. This SEM photograph is shown in FIGS. In the 300 times magnified photograph shown in FIG. 3, the region where the particles are present densely and the voids having a width of about 50 μm are distributed without regularity. In addition, in the observation photograph with a magnification of 10,000 times shown in FIG.
　得られた焼結体のＳＥＭ観察写真から、焼結体の緻密性を解析した。緻密性は、以下の方法で求めた。 From the SEM observation photograph of the obtained sintered body, the denseness of the sintered body was analyzed. Denseness was determined by the following method.
　ＳＥＭ観察写真は倍率３００倍または５００倍の画像を使用した。このとき、取得した画像の範囲は、３００倍の場合は幅３９２μｍ×高さ２８４μｍ、５００倍の場合は幅２５８μｍ×高さ１８１μｍであった。  The SEM observation photograph used an image with a magnification of 300 times or 500 times. At this time, the range of the acquired image was width 392 μm × height 284 μm in the case of 300 times, and width 258 μm × height 181 μm in the case of 500 times.
　画像は焼成体破断面のため凹凸が多い。元々空隙であったと考えられる領域は、暗い穴や、破断に伴い生じた焼結体の欠片が入り込んでいる箇所と言えるので、これら空隙と考えられる箇所が目立つように明るさ、コントラストを調節した。 The image has many irregularities due to the fracture surface of the fired body. The area that was originally thought to be a void can be said to be a place where a dark hole or a fragment of a sintered body generated due to breakage has entered, so the brightness and contrast were adjusted so that these voids were conspicuous. .
　画像処理ソフト「Ａ像くん」を用いて２値化処理を行い、空隙部分のみを抽出した。「Ａ像くん」の２値化処理による抽出では完全でない場合には手動で補った。 Binary processing was performed using image processing software “A Image-kun”, and only voids were extracted. If extraction by the binarization process of “A image” was not complete, it was manually compensated.
　空隙以外を抽出した場合は、これを削除した。 以外 Deleted other than voids.
　上記「Ａ像くん」の「総面積・個数計測」で総面積、個数、空隙面積率、計測範囲の面積を測定した。 The total area, the number, the void area ratio, and the area of the measurement range were measured by the “total area / number measurement” of “A image-kun”.
　解析の結果、ＳＥＭ観察で取得した画像領域に占める空隙部分の面積率は、２０．０％～３２．０％であった。焼結体の緻密性は１００－空隙部面積率であるので、６８．０％～８０．０％と求められた。 As a result of the analysis, the area ratio of the voids in the image area obtained by SEM observation was 20.0% to 32.0%. Since the compactness of the sintered body was 100-void area ratio, it was determined to be 68.0% to 80.0%.
　得られた焼結体を集束イオンビーム（ＦＩＢ）を用いて加工し、走査透過型電子顕微鏡（ＳＴＥＭ）及びエネルギー分散型Ｘ線分析（ＥＤＸ）を用いて観察及び元素分布分析を行った。図５及び図６は、焼結体のＳＴＥＭ写真である。また、図７は、図５に示したＳＴＥＭ写真と、その結晶粒と思われる部分及び非晶質と思われる部分の電子回折図形を示す。 The obtained sintered body was processed using a focused ion beam (FIB), and observation and element distribution analysis were performed using a scanning transmission electron microscope (STEM) and energy dispersive X-ray analysis (EDX). 5 and 6 are STEM photographs of the sintered body. FIG. 7 shows the STEM photograph shown in FIG. 5 and the electron diffraction patterns of the part that seems to be crystal grains and the part that seems to be amorphous.
　図５～図７から明らかなように、回折スポットが観測されている結晶質部分と、回折スポットが見られない非晶質部分とが存在していることがわかる。従って、非晶質の材料が、結晶粒間に分布していることがわかる。 As is apparent from FIGS. 5 to 7, it can be seen that there are a crystalline portion where a diffraction spot is observed and an amorphous portion where no diffraction spot is observed. Therefore, it can be seen that the amorphous material is distributed between the crystal grains.
　図８は、上記焼結体のＴＥＭ－ＥＤＸスペクトル分析において観察した部分のＴＥＭ写真及び図９，図１０は、粒子部分と粒子間部分のＴＥＭ－ＥＤＸスペクトルである。図１１～図２２は、上記焼結体のＴＥＭ－ＥＤＸ元素マッピング像を示す図である。このうち図１１と図１７は、ＴＥＭ－ＥＤＸ元素マッピング分析の観察箇所のＴＥＭ写真である。結晶粒子部分には、Ｓｒ及びＴａが多く分布しており、他にＢａ及びＮが検出されている。他方、非晶質部分では、Ｂａ、Ｃ及びＮが多く分布しており、微量のＳｒ及びＴａが検出されている。この結果から、ＳｒＴａＯ２ＮはＢａＣＮ２に溶解し、再析出するときに、Ｓｒの代わりにＢａが結晶格子に取り込まれており、Ｓｒ１－ｘＢａｘＴａＯ２Ｎとして粒成長していると推測され得る。また、ＢａＣＮ２中に、溶解したＳｒ及びＴａが残留したため、非晶質部分においてＳｒ及びＴａが検出されているものと考えられる。 FIG. 8 is a TEM photograph of a portion observed in the TEM-EDX spectrum analysis of the sintered body, and FIGS. 9 and 10 are TEM-EDX spectra of a particle portion and an interparticle portion. 11 to 22 are diagrams showing TEM-EDX element mapping images of the sintered body. Among these, FIG. 11 and FIG. 17 are TEM photographs of observation points in the TEM-EDX element mapping analysis. A large amount of Sr and Ta is distributed in the crystal particle portion, and Ba and N are detected in addition. On the other hand, in the amorphous part, a large amount of Ba, C, and N is distributed, and trace amounts of Sr and Ta are detected. From this result, when SrTaO 2 N is dissolved in BaCN 2 and reprecipitated, Ba is taken into the crystal lattice instead of Sr and is grown as Sr 1-x Ba x TaO 2 N. Can be guessed. Further, since dissolved Sr and Ta remain in BaCN 2 , it is considered that Sr and Ta are detected in the amorphous portion.
　上記焼結体を、破断し、破断面を研磨した。しかる後、クエン酸（Ｃ（ＯＨ）（ＣＨ２ＣＯＯＨ）２ＣＯＯＨ、９８．０％濃度）の１モル／Ｌ水溶液に２日間浸漬し、ＢａＣＮ２及びＢａＣＮ２に由来すると考えられる非晶質を除去した。浸漬後の焼結体を取り出し、少量の蒸留水及びヘキサンを用いて洗浄した。この後に、破断面をＳＥＭで観察した。図２３（ａ）及び図２３（ｂ）は、上記破断面のＳＥＭ写真である。図４の倍率１００００倍のＳＥＭ写真と比べると、同じ位置の図２３（ａ）では、粒径８０ｎｍ～４００ｎｍ程度、平均粒径で２００ｎｍ程度の角張った粒子が互いに結合しながら分布していることがわかる。破断面の複数のＳＥＭ写真に対して画像解析ソフト「Ａ像くん」を用いて粒度分布を解析した結果、円相当径の平均値は２３７ｎｍと求められた。粒子同士の空隙は、非晶質が存在した部分と考えられる。従って、非晶質が存在した部分は、大きくても、１μｍ程度と考えられる。 The sintered body was broken and the fractured surface was polished. After that, it was immersed in a 1 mol / L aqueous solution of citric acid (C (OH) (CH 2 COOH) 2 COOH, 98.0% concentration) for 2 days, and an amorphous substance considered to be derived from BaCN 2 and BaCN 2 was obtained. Removed. The sintered body after immersion was taken out and washed with a small amount of distilled water and hexane. After this, the fracture surface was observed with SEM. FIG. 23A and FIG. 23B are SEM photographs of the fracture surface. Compared to the SEM photograph at a magnification of 10000 in FIG. 4, in FIG. 23 (a) at the same position, angular particles having a particle size of about 80 nm to 400 nm and an average particle size of about 200 nm are distributed while being bonded to each other. I understand. As a result of analyzing the particle size distribution for a plurality of SEM photographs of the fracture surface using the image analysis software “A image-kun”, the average value of the equivalent circle diameter was determined to be 237 nm. The void between the particles is considered to be a portion where amorphous exists. Therefore, the portion where the amorphous material was present is considered to be about 1 μm at most.
　上記焼結体内では、ペロブスカイト構造を有する酸窒化物粒子同士の間に、非晶質が分布していることがわかった。これは、上記の通り、ＳｒＴａＯ２Ｎ粒子間の隙間に液状のＢａＣＮ２が浸透し、ＳｒＴａＯ２Ｎ粒子の溶解及び再析出による粒成長や結合を生じさせた後、液状のＢａＣＮ２は炉内温度低下に伴い固化した時に結晶化しなかったためと考えられる。 It was found that the amorphous material was distributed between the oxynitride particles having a perovskite structure in the sintered body. This, as described above, SrTaO 2 BaCN 2 liquid into the gap between the N particles penetrate, after causing grain growth or binding by dissolution and reprecipitation of SrTaO 2 N particles, liquid bit BACn 2 is a furnace This is thought to be because it did not crystallize when solidified as the temperature decreased.
　（５）焼結体の電気物性の評価
　（３）で得られた焼結体の両面に、白金（Ｐｔ）をスパッタ法を用いて成膜した。インピーダンスアナライザーを用いて、比誘電率（εｒ）、誘電損失（ｔａｎδ）及び複素インピーダンスを測定した。図２４は、複素インピーダンス特性を示す図である。図２４から、複素インピーダンスは、数ＭΩの領域にあり、焼結体が十分な絶縁性を有することがわかった。図２５に示すように、比誘電率（εｒ）は、周波数によらず６０以上、２００以下の領域に存在しており、誘電損失は７×１０－２（７％）以上、３×１０－１（３０％）以下の領域にあることがわかった。 (5) Evaluation of electrical properties of sintered body Platinum (Pt) was formed on both surfaces of the sintered body obtained in (3) using a sputtering method. Using an impedance analyzer, the relative permittivity (ε r ), dielectric loss (tan δ), and complex impedance were measured. FIG. 24 is a diagram illustrating complex impedance characteristics. From FIG. 24, it was found that the complex impedance is in the region of several MΩ, and the sintered body has sufficient insulation. As shown in FIG. 25, the relative dielectric constant (ε r ) exists in the region of 60 or more and 200 or less regardless of the frequency, and the dielectric loss is 7 × 10 −2 (7%) or more and 3 × 10. -1 (30%) and below.
　上記と同じ焼結体を、インピーダンスアナライザーを用いて周波数５ＭＨｚ～１００ＭＨｚの電場を印加し、３０℃～１５０℃の温度範囲で、比誘電率及び誘電損失を測定した。結果を、図２６に示す。温度３０℃～１５０℃の範囲で、比誘電率は周波数５ＭＨｚでは１３９～１５３に、１０ＭＨｚでは１３７～１５０に、５０ＭＨｚでは１２５～１３４に、１００ＭＨｚでは１２２～１２９に増加した。 For the same sintered body as described above, an electric field having a frequency of 5 MHz to 100 MHz was applied using an impedance analyzer, and a relative dielectric constant and a dielectric loss were measured in a temperature range of 30 ° C. to 150 ° C. The results are shown in FIG. In the temperature range of 30 ° C. to 150 ° C., the relative dielectric constant increased from 139 to 153 at a frequency of 5 MHz, from 137 to 150 at 10 MHz, from 125 to 134 at 50 MHz, and from 122 to 129 at 100 MHz.
　３０℃～１５０℃の温度範囲における比誘電率の増加量を３０℃のときの比誘電率で除算した。その結果、比誘電率の変化率は、周波数５、１０、５０、及び１００ＭＨｚにおいて、それぞれ、１０．７、９．３、６．５、５．６（％）であった。誘電損失は、０．０８（８％）以上、０．２（２０％）以下の間で変化した。 The increase in relative dielectric constant in the temperature range of 30 ° C. to 150 ° C. was divided by the relative dielectric constant at 30 ° C. As a result, the change rate of the dielectric constant was 10.7, 9.3, 6.5, 5.6 (%) at frequencies of 5, 10, 50, and 100 MHz, respectively. The dielectric loss varied between 0.08 (8%) and 0.2 (20%).
　（実施例２）
　ＢａＣＮ２のＳｒＴａＯ２Ｎに対する添加量を５０重量部としたことを除いては、実施例１と同様にして、焼結体を得た。得られた焼結体は、実施例１で得られた焼結体と同様に、加圧後の成形体に比べて収縮しており、硬質であった。また、実施例１で得た焼結体に比べ、実施例２で得た焼結体は、赤みがより強かった。 (Example 2)
Is the amount for SrTaO 2 N of bit BACn 2 except that the 50 parts by weight, in the same manner as in Example 1 to obtain a sintered body. Similar to the sintered body obtained in Example 1, the obtained sintered body was contracted and hard as compared with the formed body after pressurization. In addition, the sintered body obtained in Example 2 was more reddish than the sintered body obtained in Example 1.
　実施例２で得た焼結体が、赤みが強いことは以下の理由によると考えられる。すなわち、Ｓｒ１－ｘＢａｘＴａＯ２Ｎにおいて、ｘが実施例１の場合よりも大きいためと考えられる。言い換えれば、ＳｒＴａＯ２ＮにおけるＳｒサイトにおいて、ＳｒからＢａへの置換がより一層進んでいるためと考えられる。 It is considered that the sintered body obtained in Example 2 has a strong redness due to the following reason. That is, it is considered that x is larger in the case of Sr 1-x Ba x TaO 2 N than in the case of the first embodiment. In other words, it is considered that the substitution from Sr to Ba is further advanced at the Sr site in SrTaO 2 N.
　（実施例３）
　実施例１の（１）で得たＳｒＴａＯ２Ｎの成形体上に、該成形体の３０％の重量を有する、ＢａＣＮ２の成形体を配置し、９００℃の温度で２時間、窒素ガス中で加熱した。それによって、焼結体を得た。 (Example 3)
On the forming of SrTaO 2 N obtained in Example 1 (1), with 30% of the weight of the molded article, placing the molded article of the bit BACn 2, 2 hours, nitrogen gas at a temperature of 900 ° C. And heated. Thereby, a sintered body was obtained.
　得られた焼結体は、赤色を示し、かつ硬質であった。また、焼結体上面には、やや明るい赤色または白色の層が見られた。この焼結体を乾式研磨すると、研磨された面は光沢を有していた。 The obtained sintered body was red and hard. A slightly bright red or white layer was observed on the upper surface of the sintered body. When this sintered body was dry-polished, the polished surface was glossy.
　また、この焼結体を破断し、破断面をＳＥＭで観察した。図２７（ａ）～図２７（ｃ）は、焼結体の破断面のＳＥＭ写真を示す。破断面に、個々の粒子の形状は見られず、溶融・硬化物が分布していることがわかる。 Further, this sintered body was broken and the fracture surface was observed by SEM. 27 (a) to 27 (c) show SEM photographs of fracture surfaces of the sintered body. It can be seen that the shape of individual particles is not seen on the fracture surface, and the melted and hardened material is distributed.
　上記焼結体の破断面をＦＩＢ加工し、ＳＴＥＭ－ＥＤＸ分析を行った。図２８（ａ）及び図２８（ｂ）は、ＳＴＥＭ観察写真を示し、図２９（ａ）～図２９（ｃ）はその要部を拡大して示す。 The fracture surface of the sintered body was subjected to FIB processing and STEM-EDX analysis was performed. 28 (a) and 28 (b) show STEM observation photographs, and FIGS. 29 (a) to 29 (c) show an enlarged main part thereof.
　図２８（ａ）及び図２８（ｂ）並びに図２９（ａ）～図２９（ｃ）から、粒子同士が別の物質で結合されていることがわかる。 FIG. 28 (a), FIG. 28 (b) and FIGS. 29 (a) to 29 (c) show that the particles are bound by another substance.
　図２９（ａ）に示すＳＴＥＭ写真の結晶粒と見られる部分のＳＴＥＭ－ＥＤＸスペクトルを図３０に、結着物質部分と見られる部分のＳＴＥＭ－ＥＤＸスペクトルを図３１に示す。 FIG. 30 shows the STEM-EDX spectrum of the part seen as the crystal grain of the STEM photograph shown in FIG. 29 (a), and FIG. 31 shows the STEM-EDX spectrum of the part seen as the binding substance part.
　図３０及び図３１より、ＳｒＴａＯ２Ｎ粒子であった部分に微量のＢａが分布していること、ＢａＣＮ２部分であった結着物質部分にＳｒとＴａも分布していることがわかる。 30 and 31, it can be seen that a small amount of Ba is distributed in the portion that was the SrTaO 2 N particles, and that Sr and Ta are also distributed in the binding material portion that was the BaCN 2 portion.
　上記焼結体の研磨と、ＸＲＤ分析及び上記ＳＴＥＭ－ＥＤＸ分析を繰り返すことにより、焼結体の上面から底面に至るまでの結晶相と元素組成を分析した。図３２は、各部分のＸＲＤパターンを示す図である。また、図内のＳｒ／Ｂａ／Ｔａの右側の数字は、焼結体の各部分の蛍光Ｘ線（ＸＲＦ）分析による、Ｓｒ、Ｂａ、Ｔａの各原子の個数比率（ａｔ％）である。上面から底面に至るまで、主な結晶相がペロブスカイト構造を有し、Ｓｒ１－ｘＢａｘＴａＯ２Ｎの回折パターンを示していることがわかる。他に、Ｂａ（ＯＨ）２・Ｈ２Ｏ及びＳｒＣＯ３に由来すると考えられる微弱な回折ピークと、不明相の回折ピークが検出された。また、上面に行くほどＢａ量が多く底面に向かうにつれてＢａ量は減少した。なお、底面のみＢａ量が再度増加しているが、融解したＢａＣＮ２が酸窒化物成形体の外周部を伝って、底面側に浸透したものと考えられる。 By repeating the polishing of the sintered body, the XRD analysis, and the STEM-EDX analysis, the crystal phase and element composition from the top surface to the bottom surface of the sintered body were analyzed. FIG. 32 is a diagram showing an XRD pattern of each part. Further, the numbers on the right side of Sr / Ba / Ta in the figure are the number ratios (at%) of the respective atoms of Sr, Ba, and Ta according to the fluorescent X-ray (XRF) analysis of each part of the sintered body. From the top surface to the bottom surface, it can be seen that the main crystal phase has a perovskite structure and shows a diffraction pattern of Sr 1-x Ba x TaO 2 N. In addition, a weak diffraction peak considered to be derived from Ba (OH) 2 .H 2 O and SrCO 3 and a diffraction peak of an unknown phase were detected. Further, the amount of Ba increased toward the top surface, and the amount of Ba decreased as it moved toward the bottom surface. In addition, although the amount of Ba is increasing again only on the bottom surface, it is considered that the melted BaCN 2 penetrates the bottom surface side through the outer peripheral portion of the oxynitride molded body.
　実施例１と同様にして、この焼結体の複素インピーダンス特性を評価した。図３３は、この焼結体の複素インピーダンス特性を示す図である。図３３により、焼結体は数ＭΩの抵抗を有し、絶縁性を有することが確認された。 In the same manner as in Example 1, the complex impedance characteristic of this sintered body was evaluated. FIG. 33 is a diagram showing the complex impedance characteristic of this sintered body. FIG. 33 confirms that the sintered body has a resistance of several MΩ and has an insulating property.
　上記焼結体の誘電物性を実施例１と同様にして評価した。結果を図３４に示す。図３４より、比誘電率（εｒ）は１００前後であり、誘電損失（ｔａｎδ）は１０－１（１０％）以上、０．７（７０％）以下の間で変動していることがわかる。また、誘電物性の温度依存性を図３５及び図３６に示す。－５０℃～５０℃の１００℃の温度範囲において、印加電場の周波数ごとの比誘電率（εｒ）の増加量を下記の表１に示す。 The dielectric properties of the sintered body were evaluated in the same manner as in Example 1. The results are shown in FIG. From FIG. 34, it is understood that the relative dielectric constant (ε r ) is around 100 and the dielectric loss (tan δ) varies between 10 −1 (10%) and 0.7 (70%). . The temperature dependence of dielectric properties is shown in FIGS. Table 1 below shows the amount of increase in the relative permittivity (ε r ) for each frequency of the applied electric field in the temperature range of −50 ° C. to 50 ° C. and 100 ° C.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１から、上記温度範囲における温度変化による比誘電率（εｒ）の変化量は、周波数１ｋＨｚ、１０ｋＨｚ、１００ｋＨｚ、１ＭＨｚにおいて、それぞれ、６．２２％、４．２３％、２．９２％及び１．９４％であった。 From Table 1, the amount of change in relative permittivity (ε r ) due to temperature change in the above temperature range is 6.22%, 4.23%, 2.92%, and 1kHz at frequencies of 1 kHz, 10 kHz, 100 kHz, and 1 MHz, respectively. 1.94%.
　実施例３の結果から明らかなように、焼結助剤のシアナミドは、金属酸窒化物と混合して用いられなくともよい。すなわち、焼結助剤は、金属酸窒化物と接触されてさえいればよい。 As is clear from the results of Example 3, the sintering aid cyanamide may not be used in combination with a metal oxynitride. That is, the sintering aid only needs to be in contact with the metal oxynitride.
　（実施例４）
　実施例１の（１）で合成されたＳｒＴａＯ２Ｎ粉体２００ｍｇとＢａＣＮ２粉体３００ｍｇとを混合したのち、酸化アルミニウム製ルツボ内に設置し、実施例１と同様にして、９００℃の温度で３０時間、窒素ガス中で加熱した。熱処理後、ルツボの底面に赤茶色の固化物が形成されていた。 Example 4
After mixing 200 mg of the SrTaO 2 N powder synthesized in (1) of Example 1 and 300 mg of BaCN 2 powder, the mixture was placed in an aluminum oxide crucible, and the temperature was 900 ° C. in the same manner as in Example 1. And heated in nitrogen gas for 30 hours. After the heat treatment, a reddish brown solid was formed on the bottom of the crucible.
　上記固化物を取り出したのち、１モル／Ｌ濃度の硝酸に１５時間浸漬した。その結果、赤色の微粉末が硝酸を入れた容器の底面に沈殿した。ろ過により沈殿物を得、蒸留水で洗浄し、試料粉体とした。 The solidified product was taken out and immersed in nitric acid having a concentration of 1 mol / L for 15 hours. As a result, red fine powder precipitated on the bottom of the container containing nitric acid. A precipitate was obtained by filtration and washed with distilled water to obtain a sample powder.
　上記試料粉体の組成をＸＲＦを用いて分析した。その結果、Ｓｒ、Ｂａ及びＴａは、４１．９（２）：７．９４（４）：５０．２（３）の割合で含まれていた。Ｓｒ＋Ｂａの割合と、Ｔａの割合とがほぼ一致した。 The composition of the sample powder was analyzed using XRF. As a result, Sr, Ba, and Ta were included at a ratio of 41.9 (2): 7.94 (4): 50.2 (3). The ratio of Sr + Ba almost coincided with the ratio of Ta.
　他方、ろ液をＩＣＰ－ＡＥＳを用いて元素組成を分析した。その結果、Ｓｒ、Ｂａと、微量のＴａの存在が確認された。従って、実施例１において作製した焼結体の非晶質部分には、元のＢａＣＮ２だけでなく、ＳｒＴａＯ２Ｎ酸窒化物粒子から溶解したＳｒやＴａが含有されていると推定される。 On the other hand, the elemental composition of the filtrate was analyzed using ICP-AES. As a result, the presence of Sr, Ba and a small amount of Ta was confirmed. Therefore, it is estimated that the amorphous part of the sintered body produced in Example 1 contains not only the original BaCN 2 but also Sr and Ta dissolved from the SrTaO 2 N oxynitride particles.
　上記試料粉体をＸＲＤ分析した。結果を図３７に示す。図３７より、この試料粉体は、ＳｒＴａＯ２ＮやＢａＴａＯ２Ｎと同様のペロブスカイト型の結晶を有することがわかる。また、試料粉体の回折ピーク位置は、ＳｒＴａＯ２Ｎの回折ピーク位置と、ＢａＴａＯ２Ｎとの回折ピーク位置の間に存在した。上記ＸＲＦ分析及びＸＲＤ分析の結果から、上記試料粉体は、Ｓｒ１－ｘＢａｘＴａＯ２Ｎであることがわかった。 The sample powder was subjected to XRD analysis. The results are shown in FIG. FIG. 37 shows that this sample powder has the same perovskite crystal as SrTaO 2 N and BaTaO 2 N. The diffraction peak position of the sample powder has a diffraction peak position of SrTaO 2 N, were present during the diffraction peak position of the BaTaO 2 N. From the results of the XRF analysis and the XRD analysis, it was found that the sample powder was Sr 1-x Ba x TaO 2 N.
　上記試料粉体をＳＥＭに装着したＥＤＸを用いて、元素分布を分析した。元素マッピング像を、図３８（ａ）～図３８（ｃ）及び図３９（ａ）～図３９（ｃ）に示す。Ｓｒ、Ｂａ、Ｔａ、Ｎ及びＯが一様に分布していることが確認された。 The element distribution was analyzed using EDX in which the sample powder was mounted on an SEM. Element mapping images are shown in FIGS. 38 (a) to 38 (c) and FIGS. 39 (a) to 39 (c). It was confirmed that Sr, Ba, Ta, N and O were uniformly distributed.
　上記試料粉体をＳＥＭで観察した。図４０（ａ），図４０（ｂ）及び図４１（ａ），図４１（ｂ）は、上記のように硝酸で洗浄された粉体粒子のＳＥＭ写真である。 The sample powder was observed with SEM. 40 (a), 40 (b), 41 (a), and 41 (b) are SEM photographs of powder particles washed with nitric acid as described above.
　図４０（ａ），図４０（ｂ）及び図４１（ａ），図４１（ｂ）から、粒子の一次粒径が０．１μｍ以上、３μｍ以下程度であり、一次粒子同士が互いに強固に結合しているように見受けられた。また、二次粒子の大きさは約数μｍであった。 40 (a), 40 (b), 41 (a), and 41 (b), the primary particle size of the particles is about 0.1 μm to 3 μm, and the primary particles are firmly bonded to each other. It seemed to be. The size of the secondary particles was about several μm.
　ＢａＣＮ２をＳｒＴａＯ２Ｎよりも多くした場合、ＢａＣＮ２液相が多く生じる。これにＳｒＴａＯ２Ｎが溶解したと考えられる。その結果、酸窒化物粒子は、溶解及び再析出を繰り返しながら粒成長し、直径１μｍ以上の多結晶粒子が形成された。上記のように、一次粒径が０．１μｍ～数μｍの範囲に跨っている。これらの結果から、シアナミドを用いた液相焼結では、酸窒化物粒子が効果的に粒成長することがわかる。 When the amount of BaCN 2 is larger than that of SrTaO 2 N, a large amount of BaCN 2 liquid phase is generated. It is considered that SrTaO 2 N was dissolved in this. As a result, the oxynitride particles grew while repeating dissolution and reprecipitation, and polycrystalline particles having a diameter of 1 μm or more were formed. As described above, the primary particle size extends over the range of 0.1 μm to several μm. From these results, it is understood that oxynitride particles grow effectively in liquid phase sintering using cyanamide.
　また、上記酸窒化物粒子のシアナミド相への溶解及び再析出の繰り返しにより、大粒径であり、かつ単相の酸窒化物粒子を合成することが可能となる。 Further, by repeating dissolution and reprecipitation of the oxynitride particles in the cyanamide phase, it is possible to synthesize single-phase oxynitride particles having a large particle size.
　（実施例５）
　本実施例は、金属酸窒化物としてＬａＴａＯＮ２を用いた点において、実施例１と異なる。以下において、本実施例の詳細を説明する。 (Example 5)
This example differs from Example 1 in that LaTaON 2 is used as the metal oxynitride. Details of the present embodiment will be described below.
　酸化ランタン（Ｌａ２Ｏ３）粉体と、酸化ランタンと等モル量の酸化タンタル（Ｔａ２Ｏ５）とをエタノール分散媒中で混合した。空気中で乾燥させたのち、電気炉を用いて、大気雰囲気下で１４００℃の温度で２０時間熱処理した。それによって、ＬａＴａＯ４粉体を得た。 Lanthanum oxide (La 2 O 3 ) powder and lanthanum oxide and an equimolar amount of tantalum oxide (Ta 2 O 5 ) were mixed in an ethanol dispersion medium. After drying in the air, heat treatment was performed for 20 hours at a temperature of 1400 ° C. in an air atmosphere using an electric furnace. Thereby, LaTaO 4 powder was obtained.
　得られたＬａＴａＯ４粉体を、酸化アルミニウム（Ａｌ２Ｏ３）からなるボート上に配置し、石英ガラス炉心管を有する管状炉内に設けた。炉心管内にアンモニアガスを１００ｍｌ／分の流量で流し、１０００℃で１５時間加熱し、ＬａＴａＯＮ２粉体を合成した。管状炉温度コントローラーによる昇温速度は５℃／分、降温速度は３℃／分とした。 The obtained LaTaO 4 powder was placed on a boat made of aluminum oxide (Al 2 O 3 ) and provided in a tubular furnace having a quartz glass core tube. Ammonia gas was allowed to flow through the furnace tube at a flow rate of 100 ml / min and heated at 1000 ° C. for 15 hours to synthesize LaTaON 2 powder. The temperature rising rate by the tubular furnace temperature controller was 5 ° C./min, and the temperature lowering rate was 3 ° C./min.
　得られたＬａＴａＯＮ２粉体を粉末Ｘ線回析（ＸＲＤ）装置を用い、結晶分析を行った。その結果、ＬａＴａＯＮ２の無機結晶構造データと一致することを確認した。 The obtained LaTaON 2 powder was crystallized using a powder X-ray diffraction (XRD) apparatus. As a result, it was confirmed to be consistent with LaTaON 2 inorganic crystal structure data.
　ＬａＴａＯＮ２粉体と、実施例１の（２）で得たＢａＣＮ２粉体とを混合し、実施例１と同様の方法で成形体を作製した。このとき、ＬａＴａＯＮ２粉体に対するＢａＣＮ２粉体の添加量を３０重量部とした。ＬａＴａＯＮ２とＢａＣＮ２とのｍｏｌ比率としては６２ｍｏｌ％：３８ｍｏｌ％に相当する。成形体を、窒素ガスを流しつつ、９１５℃の温度で３０時間加熱した。得られた焼結体は固化していた。さらに、この焼結体を蒸留水に１日間浸漬したところ、焼結体は粉体状に崩れた。この粉体を遠心分離機を用いて回収・乾燥させた。 And LaTaON 2 powder, mixing the bit BACn 2 powder obtained in Example 1 (2) to produce a molded body in the same manner as in Example 1. At this time, the addition amount of the BaCN 2 powder to the LaTaON 2 powder was 30 parts by weight. The molar ratio of LaTaON 2 to BaCN 2 corresponds to 62 mol%: 38 mol%. The molded body was heated at a temperature of 915 ° C. for 30 hours while flowing nitrogen gas. The obtained sintered body was solidified. Furthermore, when this sintered body was immersed in distilled water for 1 day, the sintered body collapsed into a powder form. The powder was collected and dried using a centrifuge.
　図４２は、実施例５で得られた焼結体及び焼結体を蒸留水に浸漬させた後乾燥させて得られた粉体のＸＲＤパターンを示す図である。 FIG. 42 is a view showing an XRD pattern of a powder obtained by immersing the sintered body obtained in Example 5 and the sintered body in distilled water and then drying.
　焼結体はＬａＴａＯＮ２とＢａ２ＬａＴａＯ６とにより構成されていることがわかる。これら２つの結晶相に起因する回折ピーク強度の比率から、リートベルト法を用い結晶相の構成比率を計算したところ、ＬａＴａＯＮ２：Ｂａ２ＬａＴａＯ６＝９７．７ｍｏｌ％：２．３ｍｏｌ％と求められた。この比率は成形体の作製に使用したＬａＴａＯＮ２とＢａＣＮ２とのｍｏｌ比率（６２ｍｏｌ％：３８ｍｏｌ％）とは大きく異なっており、ＢａＣＮ２に由来する成分の多くが非晶質として焼結体中に存在していることを示している。また、蒸留水に浸漬し、乾燥したことにより得た粉体では、ＬａＴａＯＮ２及びＢａ２ＬａＴａＯ６に加えてＢａＣＯ３相が生じた。この結果から、焼結体中に存在するＢａを含む非晶質成分が水と反応してＢａＣＯ３を生じさせたと考えられる。 It can be seen that the sintered body is composed of LaTaON 2 and Ba 2 LaTaO 6 . When the composition ratio of the crystal phase was calculated from the ratio of the diffraction peak intensities caused by these two crystal phases by using the Rietveld method, it was calculated as LaTaON 2 : Ba 2 LaTaO 6 = 97.7 mol%: 2.3 mol%. It was. This ratio is greatly different from the molar ratio of LaTaON 2 and BaCN 2 (62 mol%: 38 mol%) used for the production of the molded body, and many of the components derived from BaCN 2 are amorphous in the sintered body. Is present. Further, in the powder obtained by dipping in distilled water and drying, a BaCO 3 phase was generated in addition to LaTaON 2 and Ba 2 LaTaO 6 . From this result, it is considered that the amorphous component containing Ba present in the sintered body reacted with water to generate BaCO 3 .
　図４３（ａ）及び図４３（ｂ）は、実施例５で得られた焼結体の５００倍及び１００００倍の各ＳＥＭ写真である。図４４（ａ）及び図４４（ｂ）は、実施例５において焼結体を蒸留水に浸漬させた後乾燥させて得られた粉体の５００倍及び１００００倍の各ＳＥＭ写真である。 43 (a) and 43 (b) are SEM photographs of 500 times and 10,000 times the sintered body obtained in Example 5, respectively. 44 (a) and 44 (b) are SEM photographs of 500 times and 10,000 times the powder obtained by immersing the sintered body in distilled water and drying it in Example 5. FIG.
　焼結体内部の粒子は膜状の物体に覆われている。一方で、焼結体を蒸留水に浸漬させた後乾燥させて得られた粉体の粒子は、膜状物質に覆われておらず、個々の粒子の形状が明瞭に観察された。これらの結果から、非晶質成分は結晶粒子の表面を覆っていることがわかった。 The particles inside the sintered body are covered with a film-like object. On the other hand, powder particles obtained by immersing the sintered body in distilled water and drying were not covered with a film-like substance, and the shape of each particle was clearly observed. From these results, it was found that the amorphous component covered the surface of the crystal particles.
　また、焼結体中の酸窒化物粒子の粒度分布を、実施例１と同様に、破断面の複数のＳＥＭ写真に対して画像解析ソフト「Ａ像くん」を用いて解析した。その結果、円相当径の平均値は１９５０ｎｍと求められた。 Further, the particle size distribution of the oxynitride particles in the sintered body was analyzed using the image analysis software “A image-kun” on a plurality of SEM photographs of the fracture surface in the same manner as in Example 1. As a result, the average circle equivalent diameter was determined to be 1950 nm.
　実施例１と同様にして、この焼結体の複素インピーダンス特性を評価した。図４５は、この焼結体の複素インピーダンス特性を示す図である。図４５により、焼結体は数ＭΩの抵抗を有し、絶縁性を有することが確認された。 In the same manner as in Example 1, the complex impedance characteristic of this sintered body was evaluated. FIG. 45 is a diagram showing the complex impedance characteristic of this sintered body. FIG. 45 confirmed that the sintered body had a resistance of several MΩ and had insulating properties.
　上記焼結体の誘電物性を実施例１と同様にして評価した。結果を図４６に示す。図４６より、比誘電率（εｒ）は１０以上、４０以下程度であり、誘電損失（ｔａｎδ）は０．１（１０％）以上、０．６（６０％）以下の間で変動していることがわかる。 The dielectric properties of the sintered body were evaluated in the same manner as in Example 1. The results are shown in FIG. From FIG. 46, the relative dielectric constant (ε r ) is about 10 or more and 40 or less, and the dielectric loss (tan δ) varies between 0.1 (10%) and 0.6 (60%) or less. I understand that.
　このように、本発明の焼結体には、例えばＬａＴａＯＮ２などの、ＳｒＴａＯ２Ｎ以外の金属酸窒化物も用い得る。 Thus, the sintered body of the present invention, such as for example LaTaON 2, may also be used metal oxynitride non SrTaO 2 N.
　上記焼結体の破断面をＦＩＢ加工し、ＳＴＥＭ－ＥＤＸ分析を行った。 The fracture surface of the sintered body was subjected to FIB processing and STEM-EDX analysis was performed.
　図４７は、ＳＴＥＭ観察写真と電子線回折像を示す。また、ＳＴＥＭ－ＥＤＸ元素マッピングを図４８に示す。 FIG. 47 shows a STEM observation photograph and an electron beam diffraction image. Further, STEM-EDX element mapping is shown in FIG.
　図４７に示すように、結晶粒の周囲には、結晶質であることを示す電子線回折パターンが得られない非晶質部分があることがわかる。また図４８に示すように、結晶粒の表層部分には、Ｃ、Ｂａ及びＮが多く検出された。この結果から、酸窒化物結晶粒子同士を結着する結晶粒間の部分は、主にＢａとＣからなる化合物で形成されていることがわかった。なお、結晶粒の表層部分の層には、少量だがＬａが含まれることもわかる。 As shown in FIG. 47, it can be seen that there is an amorphous portion around the crystal grain where an electron beam diffraction pattern indicating that it is crystalline cannot be obtained. Further, as shown in FIG. 48, a large amount of C, Ba and N were detected in the surface layer portion of the crystal grains. From this result, it was found that the portion between the crystal grains binding the oxynitride crystal particles was mainly formed of a compound composed of Ba and C. It can also be seen that the surface layer portion of the crystal grains contains a small amount of La.
　（実施例６）
　本実施例は、金属酸窒化物としてＢａＴａＯ２Ｎを用いた点において、実施例１と異なる。以下において、本実施例の詳細を説明する。 (Example 6)
This example differs from Example 1 in that BaTaO 2 N is used as the metal oxynitride. Details of the present embodiment will be described below.
　炭酸バリウム（ＢａＣＯ３）粉体と、炭酸バリウム１．０２モル当量に対し０．５モル当量の酸化タンタル（Ｔａ２Ｏ５）とを、エタノール分散媒中で混合した。空気中で乾燥させて得た粉体を、酸化アルミニウム（Ａｌ２Ｏ３）からなるボート上に配置し、石英ガラス炉心管を有する管状炉内に設けた。炉心管内にアンモニアガスを１００ｍｌ／分の流量で流し、９５０℃で８０時間加熱し、ＢａＴａＯ２Ｎ粉体を合成した。管状炉温度コントローラーによる昇温速度は５℃／分、降温速度は３℃／分とした。 Barium carbonate (BaCO 3 ) powder and 0.5 molar equivalent of tantalum oxide (Ta 2 O 5 ) with respect to 1.02 molar equivalent of barium carbonate were mixed in an ethanol dispersion medium. The powder obtained by drying in air was placed on a boat made of aluminum oxide (Al 2 O 3 ) and provided in a tubular furnace having a quartz glass furnace tube. Ammonia gas was allowed to flow through the furnace tube at a flow rate of 100 ml / min and heated at 950 ° C. for 80 hours to synthesize BaTaO 2 N powder. The temperature rising rate by the tubular furnace temperature controller was 5 ° C./min, and the temperature lowering rate was 3 ° C./min.
　得られたＢａＴａＯ２Ｎ粉体を粉末Ｘ線回析（ＸＲＤ）装置を用い、結晶分析を行った。その結果、ＢａＴａＯ２Ｎの無機結晶構造データと一致することを確認した。 The obtained BaTaO 2 N powder was subjected to crystal analysis using a powder X-ray diffraction (XRD) apparatus. As a result, it was confirmed that it coincided with the inorganic crystal structure data of BaTaO 2 N.
　ＢａＴａＯ２Ｎ粉体と、実施例１の（２）で得たＢａＣＮ２粉体とを混合し、実施例１と同様の方法で成形体を作製した。このとき、ＢａＴａＯ２Ｎ粉体に対するＢａＣＮ２粉体の添加量を１０重量部とした。成形体を、窒素ガスを流しつつ、９００℃の温度で１０時間加熱した。得られた焼結体は固化していた。 The BaTaO 2 N powder and the BaCN 2 powder obtained in (2) of Example 1 were mixed, and a compact was produced in the same manner as in Example 1. At this time, the amount of BaCN 2 powder added to the BaTaO 2 N powder was 10 parts by weight. The molded body was heated at a temperature of 900 ° C. for 10 hours while flowing nitrogen gas. The obtained sintered body was solidified.
　図４９は、実施例６で得られた焼結体のＸＲＤパターンを示す図である。 FIG. 49 is a view showing an XRD pattern of the sintered body obtained in Example 6. FIG.
　図４９に示す焼結体のＸＲＤパターンからは、ＢａＴａＯ２Ｎと、微量のＢａ２ＴａＯ３Ｎの回折ピークが見られた。一方で、材料として用いたＢａＣＮ２成分に由来する回折ピークが見られないことがわかる。このため、実施例１と同様に、焼結体中にはＢａＣＮ２に由来する非晶質成分が含まれている。 From the XRD pattern of the sintered body shown in FIG. 49, diffraction peaks of BaTaO 2 N and a small amount of Ba 2 TaO 3 N were observed. On the other hand, it turns out that the diffraction peak derived from BaCN 2 component used as material is not seen. For this reason, as in Example 1, the sintered body contains an amorphous component derived from BaCN 2 .
　図５０（ａ）～図５０（ｃ）は、実施例６で得られた焼結体の５００倍、１０００倍及び１５０００倍の各ＳＥＭ写真である。 50 (a) to 50 (c) are SEM photographs of 500 times, 1000 times, and 15000 times that of the sintered body obtained in Example 6. FIG.
　角張った粒子が互いに結合しながら分布していることがわかる。また、焼結体中の酸窒化物粒子の粒度分布を、実施例１と同様に、破断面の複数のＳＥＭ写真に対して画像解析ソフト「Ａ像くん」を用いて解析した。その結果、円相当径の平均値は１０４１ｎｍと求められた。 It can be seen that angular particles are distributed while being bonded to each other. In addition, the particle size distribution of the oxynitride particles in the sintered body was analyzed using the image analysis software “A image-kun” on a plurality of SEM photographs of the fracture surface, as in Example 1. As a result, the average circle equivalent diameter was determined to be 1041 nm.
　実施例１と同様にして、この焼結体の複素インピーダンス特性を評価した。図５１は、この焼結体の複素インピーダンス特性を示す図である。図５１により、焼結体は数ＭΩの抵抗を有し、絶縁性を有することが確認された。 In the same manner as in Example 1, the complex impedance characteristic of this sintered body was evaluated. FIG. 51 is a diagram showing the complex impedance characteristic of this sintered body. From FIG. 51, it was confirmed that the sintered body had a resistance of several MΩ and had insulating properties.
　上記焼結体の誘電物性を実施例１と同様にして評価した。結果を図５２に示す。図５２より、比誘電率（εｒ）は４以上、４０以下程度であり、誘電損失（ｔａｎδ）は０．０６（６％）以上、０．７（７０％）以下の間で変動していることがわかる。この結果から、この焼結体は誘電体組成物に好適に用いることができることがわかる。 The dielectric properties of the sintered body were evaluated in the same manner as in Example 1. The results are shown in FIG. From FIG. 52, the relative dielectric constant (ε r ) is about 4 or more and 40 or less, and the dielectric loss (tan δ) varies between 0.06 (6%) or more and 0.7 (70%) or less. I understand that. From this result, it can be seen that this sintered body can be suitably used for a dielectric composition.
　上記焼結体の破断面をＦＩＢ加工し、ＴＥＭ－ＥＤＸ分析を行った。 The fracture surface of the sintered body was subjected to FIB processing and TEM-EDX analysis was performed.
　図５３は、ＴＥＭ観察写真と、写真中の結晶粒と見られる部分の電子線回折像を示す。図５３に示すＴＥＭ写真の結晶粒と見られる部分のＴＥＭ－ＥＤＸスペクトルを図５４に、結着物質部分と見られる部分のＴＥＭ－ＥＤＸスペクトルを図５５に示す。 FIG. 53 shows a TEM observation photograph and an electron diffraction image of a portion seen as a crystal grain in the photograph. FIG. 54 shows a TEM-EDX spectrum of a part seen as a crystal grain in the TEM photograph shown in FIG. 53, and FIG. 55 shows a TEM-EDX spectrum of a part seen as a binder substance part.
　図５３に示すように結晶粒と見られる部分で結晶質に起因する電子線の回折スポットが観察された。また、この結晶質部分には図５４に示すように、Ｂａ、Ｔａ、Ｏ、Ｎ並びにＴＥＭ観察用試料台の成分であるＷ及びＭｏが多く検出された。一方で図５５に示すように、結晶粒以外の部分ではＢａ並びにＷ及びＭｏのみが主に検出された。この結果から、酸窒化物結晶粒子同士を結着する結晶粒間の部分は、主にＢａからなる化合物で形成されていることがわかった。 As shown in FIG. 53, a diffraction spot of an electron beam due to crystallinity was observed in a portion that was seen as a crystal grain. Further, as shown in FIG. 54, a large amount of Ba, Ta, O, N, and W and Mo, which are components of the TEM observation sample stage, were detected in this crystalline portion. On the other hand, as shown in FIG. 55, only Ba, W, and Mo were mainly detected in portions other than the crystal grains. From this result, it was found that the portion between the crystal grains that bind the oxynitride crystal grains to each other is mainly formed of a compound made of Ba.
　以上のように、本発明の焼結体には、例えばＢａＴａＯ２Ｎなどの、ＳｒＴａＯ２Ｎ以外の金属酸窒化物も用い得る。 As described above, the sintered body of the present invention, for example BaTaO such 2 N, may also be used metal oxynitride non SrTaO 2 N.
　（実施例７）
　酸化ランタン（Ｌａ２Ｏ３）粉体と、酸化ランタン１モル当量に対し、２モル当量の酸化チタン（ＴｉＯ２）粉体とをエタノール分散媒中で混合した。得られた混合粉体を１２００℃の温度で３０時間熱処理した。それによって、Ｌａ２Ｔｉ２Ｏ７粉体を得た。 (Example 7)
Lanthanum oxide (La 2 O 3 ) powder and 2 molar equivalents of titanium oxide (TiO 2 ) powder with respect to 1 molar equivalent of lanthanum oxide were mixed in an ethanol dispersion medium. The obtained mixed powder was heat-treated at a temperature of 1200 ° C. for 30 hours. Thereby, La 2 Ti 2 O 7 powder was obtained.
　得られたＬａ２Ｔｉ２Ｏ７粉体を、実施例１とほぼ同様に、アンモニアガスを流し、９８０℃で２０時間加熱し、ＬａＴｉＯ２Ｎ粉体を合成した。 The obtained La 2 Ti 2 O 7 powder was flowed with ammonia gas and heated at 980 ° C. for 20 hours in substantially the same manner as in Example 1 to synthesize LaTiO 2 N powder.
　ＬａＴｉＯ２Ｎ粉体と、実施例１の（２）で得たＢａＣＮ２粉体とを混合し、実施例１と同様の方法で成形体を作製した。このとき、ＬａＴｉＯ２Ｎ粉体に対するＢａＣＮ２粉体の添加量を１０重量部、２０重量部または３０重量部とした。成形体を、窒素ガスを流しつつ、９５０℃の温度で１０時間加熱した。得られた焼成物は固化しておらず、粉体の圧縮成形体様であった。 A LaTiO 2 N powder and the BaCN 2 powder obtained in (1) of Example 1 were mixed, and a compact was produced in the same manner as in Example 1. At this time, the addition amount of the BaCN 2 powder to the LaTiO 2 N powder was 10 parts by weight, 20 parts by weight or 30 parts by weight. The molded body was heated at a temperature of 950 ° C. for 10 hours while flowing nitrogen gas. The obtained fired product was not solidified and was like a powder compact.
　図５６は、実施例７で得られた焼結体のＸＲＤパターンである。 FIG. 56 is an XRD pattern of the sintered body obtained in Example 7.
　焼結体は、ＬａＴｉＯ２Ｎの他に酸化ランタン(Ｌａ２Ｏ３)、窒化チタン(ＴｉＮ)及びチタン酸二バリウム(Ｂａ２ＴｉＯ４)で構成されていた。ＳｒＴａＯ２Ｎ＋ＢａＣＮ２、ＢａＴａＯ２Ｎ＋ＢａＣＮ２及びＬａＴａＯＮ２＋ＢａＣＮ２の焼結体に関する実施例とは異なり、固化した焼結体を得られないことがわかった。これは、文献（Ｓｏｌｉｄ　Ｓｔａｔｅ　Ｓｃｉｅｎｃｅｓ，　ｖｏｌ．５４，　２－６ページ，　２０１６年、Ｐａｒｔｉａｌ　ｎｉｔｒｏｇｅｎ　ｌｏｓｓ　ｉｎ　ＳｒＴａＯ２Ｎ　ａｎｄ　ＬａＴｉＯ２Ｎ　ｏｘｙｎｉｔｒｉｄｅ　ｐｅｒｏｖｓｋｉｔｅｓ、著者Ｄａｉｘｉ　Ｃｈｅｎ，　Ｄａｉｋｉ　Ｈａｂｕ，　Ｙｕｊｉ　Ｍａｓｕｂｕｃｈｉ，　Ｓｈｕｋｉ　Ｔｏｒｉｉ，　Ｔａｋａｓｈｉ　Ｋａｍｉｙａｍａ，　Ｓｈｉｎｉｃｈｉ　Ｋｉｋｋａｗａ）において示されている通り、ＬａＴｉＯ２Ｎは８００℃からＮの脱離や熱分解が生じることが一因である。ＢａＣＮ２が融解して焼結助剤として作用し始める前に、この熱分解により、ＴｉＮやＬａ２Ｏ３といった別種の化合物相が生じるので、ＬａＴｉＯ２ＮではＢａＣＮ２を用いた焼結が進行しない。一方で、同文献には、ＳｒＴａＯ２ＮからのＮの脱離や熱分解は９５０℃以上で生じると記載されている。これらの結果から、ＢａＣＮ２を用いた焼結は、ＢａＣＮ２の融点である９００℃でＮの脱離や熱分解が生じない組成の酸窒化物で有効と考えられる。 In addition to LaTiO 2 N, the sintered body was composed of lanthanum oxide (La 2 O 3 ), titanium nitride (TiN), and dibarium titanate (Ba 2 TiO 4 ). Unlike the examples relating to sintered bodies of SrTaO 2 N + BaCN 2 , BaTaO 2 N + BaCN 2 and LaTaON 2 + BaCN 2 , it was found that a solidified sintered body could not be obtained. This is, literature (Solid State Sciences, vol.54, 2-6 pages, 2016, Partial nitrogen loss in SrTaO 2 N and LaTiO 2 N oxynitride perovskites, author Daixi Chen, Daiki Habu, Yuji Masubuchi , Shuki Torii, Takashi Kamiyama , Shinichi Kikkawa), LaTiO 2 N is partly due to the desorption and thermal decomposition of N from 800 ° C. Before BaCN 2 melts and begins to act as a sintering aid, this thermal decomposition produces another type of compound phase such as TiN or La 2 O 3, so LaTiO 2 N undergoes sintering using BaCN 2 do not do. On the other hand, the literature describes that desorption and thermal decomposition of N from SrTaO 2 N occur at 950 ° C. or higher. From these results, it is considered that sintering using BaCN 2 is effective for oxynitrides having a composition in which N desorption and thermal decomposition do not occur at 900 ° C., which is the melting point of BaCN 2 .

Claims (28)

  1. 　金属酸窒化物を含む複数の結晶粒と、非晶質との集合体を含む、焼結体。 A sintered body containing an aggregate of a plurality of crystal grains containing metal oxynitride and amorphous.
  2. 　前記非晶質が、前記結晶粒間の界面に存在している、請求項１に記載の焼結体。 The sintered body according to claim 1, wherein the amorphous is present at an interface between the crystal grains.
  3. 　前記複数の結晶粒が多結晶からなり、
    　前記非晶質が前記多結晶の結晶粒界に沿って存在する、請求項２に記載の焼結体。     The plurality of crystal grains are polycrystalline;
    The sintered body according to claim 2, wherein the amorphous exists along a grain boundary of the polycrystalline.
  4. 　前記非晶質が炭素を含む、請求項１～３のいずれか一項に記載の焼結体。 The sintered body according to any one of claims 1 to 3, wherein the amorphous material contains carbon.
  5. 　前記非晶質が、炭素と窒素とを含む、請求項１～３のいずれか一項に記載の焼結体。 The sintered body according to any one of claims 1 to 3, wherein the amorphous material contains carbon and nitrogen.
  6. 　前記非晶質は、前記金属酸窒化物の金属元素と同種の元素を少なくとも１つ含む、請求項１～５のいずれか一項に記載の焼結体。 6. The sintered body according to claim 1, wherein the amorphous material contains at least one element of the same kind as the metal element of the metal oxynitride.
  7. 　前記集合体の緻密性が６５％以上である、請求項１～６のいずれか一項に記載の焼結体。 The sintered body according to any one of claims 1 to 6, wherein the denseness of the aggregate is 65% or more.
  8. 　前記集合体の少なくとも一部の緻密性が、８０％以上である、請求項７に記載の焼結体。 The sintered body according to claim 7, wherein the denseness of at least a part of the aggregate is 80% or more.
  9. 　前記結晶粒の円相当径の平均値が０．１８μｍ以上である、請求項１～８のいずれか一項に記載の焼結体。 The sintered body according to any one of claims 1 to 8, wherein an average value of equivalent circle diameters of the crystal grains is 0.18 µm or more.
  10. 　前記結晶粒の円相当径の平均値が４．０μｍ以下である、請求項９に記載の焼結体。 The sintered body according to claim 9, wherein an average value of equivalent circle diameters of the crystal grains is 4.0 µm or less.
  11. 　前記複数の結晶粒が、ペロブスカイト構造を含む、請求項１～１０のいずれか一項に記載の焼結体。 The sintered body according to any one of claims 1 to 10, wherein the plurality of crystal grains include a perovskite structure.
  12. 　前記金属酸窒化物の金属は、アルカリ土類金属及び希土類金属のうち少なくとも一方を含む、請求項１１に記載の焼結体。 The sintered body according to claim 11, wherein the metal of the metal oxynitride includes at least one of an alkaline earth metal and a rare earth metal.
  13. 　前記金属酸窒化物の金属は、Ｌａ、Ｂａ及びＳｒから選択される少なくとも一種である、請求項１２に記載の焼結体。 The sintered body according to claim 12, wherein the metal of the metal oxynitride is at least one selected from La, Ba, and Sr.
  14. 　請求項１～１３のいずれか１項に記載の焼結体からなる誘電体組成物であって、
    　前記焼結体は、３０℃～１５０℃の環境において、５ＭＨｚ～１００ＭＨｚの電場が印加された際の比誘電率が、１００以上、２００以下である、誘電体組成物。     A dielectric composition comprising the sintered body according to any one of claims 1 to 13,
    The sintered body is a dielectric composition having a relative dielectric constant of 100 or more and 200 or less when an electric field of 5 MHz to 100 MHz is applied in an environment of 30 ° C. to 150 ° C.
  15. 　請求項１～１３のいずれか１項に記載の焼結体からなる誘電体組成物であって、
    　前記焼結体は、３０℃～１５０℃の温度範囲内での温度変化による、５ＭＨｚ～１００ＭＨｚの電場が印加された際の比誘電率の変化率が１０％以内である、誘電体組成物。     A dielectric composition comprising the sintered body according to any one of claims 1 to 13,
    The sintered body is a dielectric composition in which a change rate of a relative dielectric constant is within 10% when an electric field of 5 MHz to 100 MHz is applied due to a temperature change within a temperature range of 30 ° C. to 150 ° C.
  16. 　前記金属酸窒化物の前記結晶粒と、前記非晶質との前記集合体は、１ＭＨｚの電場が印加された場合に、－５０℃～５０℃の温度範囲内での温度変化による、比誘電率の変化率が３％以内である、請求項１４または１５に記載の誘電体組成物。 The aggregate of the crystal grains of the metal oxynitride and the amorphous material has a dielectric constant caused by a temperature change within a temperature range of −50 ° C. to 50 ° C. when an electric field of 1 MHz is applied. The dielectric composition according to claim 14 or 15, wherein the rate of change of the rate is within 3%.
  17. 　請求項１４～１６のいずれか一項に記載の誘電体組成物と、
    　前記誘電体組成物を介して対向されている一対の電極とを備える、キャパシタ。     The dielectric composition according to any one of claims 14 to 16, and
    A capacitor comprising a pair of electrodes opposed via the dielectric composition.
  18. 　請求項１～１３のいずれか一項に記載の焼結体を含む、光触媒組成物。 A photocatalyst composition comprising the sintered body according to any one of claims 1 to 13.
  19. 　請求項１～１３のいずれか一項に記載の焼結体を含む、光電変換素子。 A photoelectric conversion element comprising the sintered body according to any one of claims 1 to 13.
  20. 　請求項１～１３のいずれか一項に記載の焼結体を含む、ガスセンサ。 A gas sensor comprising the sintered body according to any one of claims 1 to 13.
  21. 　金属酸窒化物と、シアナミドを含む焼結助剤とが互いに接触された状態で、窒素を含む雰囲気中で焼結することを特徴とする、焼結体の製造方法。 A method for producing a sintered body, wherein the metal oxynitride and a sintering aid containing cyanamide are in contact with each other and sintered in an atmosphere containing nitrogen.
  22. 　前記シアナミドの融点は、前記金属酸窒化物の窒素脱離温度よりも低い、請求項２１に記載の焼結体の製造方法。 The method for producing a sintered body according to claim 21, wherein a melting point of the cyanamide is lower than a nitrogen desorption temperature of the metal oxynitride.
  23. 　前記シアナミドがＢａＣＮ２である、請求項２１または２２に記載の焼結体の製造方法。 Wherein cyanamide is bit BACn 2, the production method of the sintered body according to claim 21 or 22.
  24. 　前記金属酸窒化物は、前記シアナミドが融解した液相に溶解する材料である、請求項２１～２３のいずれか一項に記載の焼結体の製造方法。 The method for producing a sintered body according to any one of claims 21 to 23, wherein the metal oxynitride is a material that dissolves in a liquid phase in which the cyanamide is melted.
  25. 　前記金属酸窒化物は、ＢａＴａＯ２Ｎ及びＳｒＴａＯ２Ｎから選択される一種である、請求項２１～２４のいずれか１項に記載の焼結体の製造方法。 The method for producing a sintered body according to any one of claims 21 to 24, wherein the metal oxynitride is a kind selected from BaTaO 2 N and SrTaO 2 N.
  26. 　前記焼結に際し、８８０℃以上、９５０℃以下の温度で加熱する、請求項２１～２５のいずれか一項に記載の焼結体の製造方法。 The method for producing a sintered body according to any one of claims 21 to 25, wherein the sintering is performed at a temperature of 880 ° C or higher and 950 ° C or lower.
  27. 　前記焼結助剤は、前記金属酸窒化物１００重量％に対し、３重量％以上、５０重量％以下の割合で用いられる、請求項２１～２６のいずれか１項に記載の焼結体の製造方法。 The sintered body according to any one of claims 21 to 26, wherein the sintering aid is used in a ratio of 3 wt% to 50 wt% with respect to 100 wt% of the metal oxynitride. Production method.
  28. 　前記焼結助剤は、粉体状又は粒子状であり、前記金属酸窒化物に混合された状態で、前記焼結が行われる、請求項２１～２７のいずれか一項に記載の焼結体の製造方法。 The sintering according to any one of claims 21 to 27, wherein the sintering aid is in the form of powder or particles, and the sintering is performed in a state of being mixed with the metal oxynitride. Body manufacturing method.
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3764388A1 (en) * 2019-07-08 2021-01-13 Commissariat à l'Energie Atomique et aux Energies Alternatives Method for analysing by electronic microscopy
WO2021049618A1 (en) * 2019-09-12 2021-03-18 国立大学法人北海道大学 Sintered body, method for producing same, and dielectric composition
JP2021121574A (en) * 2020-01-31 2021-08-26 Tdk株式会社 Metal oxynitride powder and metal oxynitride fired body

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3078287B1 (en) * 1999-03-12 2000-08-21 ティーディーケイ株式会社 Manufacturing method of electron emission material
JP2001181053A (en) * 1999-12-22 2001-07-03 Sumitomo Electric Ind Ltd Silicon nitride sintered product and method for producing the same
JP2007175659A (en) * 2005-12-28 2007-07-12 Niigata Univ Tantalic oxynitride photocatalyst and its manufacturing method
WO2017135298A1 (en) * 2016-02-01 2017-08-10 Tdk株式会社 Dielectric porcelain composition and electronic component

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3078287B1 (en) * 1999-03-12 2000-08-21 ティーディーケイ株式会社 Manufacturing method of electron emission material
JP2001181053A (en) * 1999-12-22 2001-07-03 Sumitomo Electric Ind Ltd Silicon nitride sintered product and method for producing the same
JP2007175659A (en) * 2005-12-28 2007-07-12 Niigata Univ Tantalic oxynitride photocatalyst and its manufacturing method
WO2017135298A1 (en) * 2016-02-01 2017-08-10 Tdk株式会社 Dielectric porcelain composition and electronic component

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3764388A1 (en) * 2019-07-08 2021-01-13 Commissariat à l'Energie Atomique et aux Energies Alternatives Method for analysing by electronic microscopy
FR3098641A1 (en) * 2019-07-08 2021-01-15 Commissariat A L'energie Atomique Et Aux Energies Alternatives Analysis method by electron microscopy
US11686693B2 (en) 2019-07-08 2023-06-27 Commissariat à l'Energie Atomique et aux Energies Alternatives Electron microscopy analysis method
WO2021049618A1 (en) * 2019-09-12 2021-03-18 国立大学法人北海道大学 Sintered body, method for producing same, and dielectric composition
JPWO2021049618A1 (en) * 2019-09-12 2021-03-18
CN114423722A (en) * 2019-09-12 2022-04-29 国立大学法人北海道大学 Sintered body, method for producing same, and dielectric composition
JP7333028B2 (en) 2019-09-12 2023-08-24 国立大学法人北海道大学 Sintered body, its manufacturing method, and dielectric composition
CN114423722B (en) * 2019-09-12 2023-11-24 国立大学法人北海道大学 Sintered body, method for producing same, and dielectric composition
JP2021121574A (en) * 2020-01-31 2021-08-26 Tdk株式会社 Metal oxynitride powder and metal oxynitride fired body
JP7324458B2 (en) 2020-01-31 2023-08-10 Tdk株式会社 Metal oxynitride powder and metal oxynitride sintered body

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