JPWO2014003061A1 - Ferrite sintered body, ferrite core and coil component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ferrite sintered body having a high specific resistance, magnetic permeability and Curie temperature, a ferrite core and a coil component formed by winding a metal wire around the ferrite core. The main component is an oxide composed of Fe, Zn, Ni, and Cu. Of 100 mol% of the main component, Fe is 49 mol% or more and 50 mol% or less in terms of Fe2O3, and Zn is 32 in terms of ZnO. 2% obtained by X-ray diffraction is 35 ° or more, containing from mol% to 34 mol%, Ni containing from 10 mol% to 12.5 mol% in terms of NiO, and Cu from 4 mol% to 8 mol% in terms of CuO. A ferrite sintered body having an I 2 / I 1 of 0.350 or more and 0.380 or less, when the X-ray diffraction peak intensity at 36 ° or less is I1, and 2θ is 29.5 ° or more and 30.5 ° or less is I2. [Selection] Figure 1

Description

  The present invention relates to a ferrite sintered body, a ferrite core made of the ferrite sintered body, and a coil component formed by winding a metal wire around the ferrite core.

  Conventionally, ferrite sintered bodies have been used for cores for inductors, transformers, ballasts, electromagnets, noise filters, etc., and cores for pulse transformers used in LAN interface parts of various IT-related devices. And as a ferrite sintered compact used for this core, the Mn-Zn type ferrite sintered compact with high magnetic permeability was generally used widely.

  However, the Mn-Zn ferrite sintered body has a low specific resistance (electrical resistance) and cannot be wound directly on the ferrite sintered body serving as a core, and an insulator must be interposed therebetween. Therefore, workability of the metal wire winding was bad. In addition, since an insulator has to be interposed between them, it has been difficult to cope with downsizing and thinning that have been increasingly demanded in recent years.

On the other hand, a Ni-Zn ferrite sintered body is known as having a specific resistance approximately two orders of magnitude higher than that of a Mn-Zn ferrite sintered body. , zinc oxide, comprises a main component constituted by nickel oxide and copper oxide, the content of the oxides of the main component 100 mol%, iron oxide: in terms of Fe ₂ O ₃ 49.15 to 49.65 mol%, There has been proposed a ferrite having zinc oxide: ZnO: 32.35 to 32.85 mol%, nickel oxide: NiO: 11.90-12.30 mol%, copper oxide: CuO, 5.25-6.55 mol%.

JP 2006-206415 A

  According to the description of Examples, the ferrite described in Patent Document 1 has a Curie temperature of 100 ° C. or higher and the highest magnetic permeability of 2650, but nowadays, a ferrite having a higher magnetic permeability. There is a need for a sintered body. However, if the magnetic permeability is increased, the Curie temperature tends to be lowered, and the lower Curie temperature means that the magnetic properties in a high temperature environment are remarkably lowered. There is a need for a ferrite sintered body having a high magnetic permeability and a Curie temperature.

  An object of the present invention is to provide a ferrite sintered body having a high specific resistance, magnetic permeability and Curie temperature, a ferrite core made of the ferrite sintered body, and a coil component formed by winding a metal wire around the ferrite core. It is.

Fe, Zn, as main components ferrite comprising an oxide of Ni and Cu, among the composition 100 mol% of the main component, Fe and Fe ₂ O ₃ 50 mol% 49 mol% or more in terms of less, ZnO converted Zn A ferrite sintered body containing 32 mol% or more and 34 mol% or less in terms of Ni, 10 mol% or more and 12.5 mol% or less in terms of NiO, and Cu in an amount of 4 mol% or more and 8 mol% or less in terms of CuO. When the X-ray diffraction peak intensity when 2θ is 35 ° or more and 36 ° or less obtained by the method is I ₁ , and the X-ray diffraction peak intensity when 2θ is 29.5 ° or more and 30.5 ° or less is I ₂ , I ₂ / I ₁ is It is 0.350 or more and 0.380 or less.

  The ferrite core of the present invention is characterized by comprising a ferrite sintered body having the above-described configuration.

  Furthermore, the coil component of the present invention is characterized in that a metal wire is wound around the ferrite core having the above-described configuration.

  According to the ferrite sintered body of the present invention, a ferrite sintered body having high specific resistance, magnetic permeability, and Curie temperature can be obtained.

  According to the ferrite core of the present invention, a ferrite core having excellent characteristics can be obtained by comprising the ferrite sintered body having the above-described configuration having a high specific resistance, magnetic permeability, and Curie temperature.

  According to the coil component of the present invention, by wrapping a metal wire around the ferrite core having the above-described configuration with high specific resistance, magnetic permeability and Curie temperature, it is possible to cope with downsizing and thinning, as well as excellent characteristics and reliability. Coil components with high height.

An example of the ferrite core which consists of a ferrite sintered compact of this embodiment is shown, (a) is a perspective view of a toroidal core, (b) is a perspective view of a bobbin core.

  The ferrite sintered body, ferrite core, and coil component of the present invention will be described below. The ferrite sintered body of this embodiment is a ferrite core made of this ferrite sintered body alone or as a coil component in which a metal wire is wound around the ferrite core, for example, an inductor, a transformer, It is used for noise filters and pulse transformers for the purpose of noise reduction and electromagnets.

  Here, there are various types of ferrite cores, for example, a ring-shaped toroidal core 1 shown in the perspective view of FIG. 1A, a bobbin-shaped bobbin core 2 shown in the perspective view of FIG. There is.

The ferrite sintered body that becomes such a ferrite core is required to have a high specific resistance, magnetic permeability, and Curie temperature. As a ferrite sintered body that satisfies such requirements, the ferrite sintered body of the present embodiment can be used. body has, Fe, Zn, as main components ferrite comprising an oxide of Ni and Cu, among the composition 100 mol% of the main component, the terms of Fe ₂ O ₃ 49 mol% Fe 50 mol% or less, Zn Containing 32 mol% or more and 34 mol% or less in terms of ZnO, Ni containing 10 mol% or more and 12.5 mol% or less in terms of NiO, Cu containing 4 mol% or more and 8 mol% or less in terms of CuO, and obtained by X-ray diffraction. 2 [Theta] is I ₁ X-ray diffraction peak intensity definitive to 35 ° over 36 ° or less, 2 [Theta] is the X-ray diffraction peak intensity definitive below 30.5 ° 29.5 ° or more when the I _2, I ₂ / I ₁ is 0.350 or more 0.380 or less It is characterized by being . As specific values, the specific resistance can be 10 ⁹ Ω · m or more, the magnetic permeability can be 3000 or more, and the Curie temperature can be 90 ° C. or more.

Here, the reason why the main component is in the above-described composition range is that when Fe is less than 49 mol% in terms of Fe ₂ O ₃ , the magnetic permeability decreases, and when it exceeds 50 mol%, the specific resistance decreases. Moreover, if Zn is less than 32 mol% in terms of ZnO, the magnetic permeability is low, and if it exceeds 34 mol%, the Curie temperature is low. Further, when Ni is less than 10 mol% in terms of NiO, the Curie temperature is low, and when it is 12.5 mol% or more, the magnetic permeability is low.

  Moreover, if Cu is less than 4 mol% in terms of CuO, the magnetic permeability is low, and if it exceeds 8 mol%, the Curie temperature is low. In addition, the main component here means the component which occupies 95 mass% or more among all the components which comprise a ferrite sintered compact, and it is suitable that it is 99 mass% or more. Moreover, the ratio of the mol% value of Ni in terms of NiO and the mol% value of Zn in terms of ZnO (mol% value in terms of ZnO / mol% value in terms of NiO) is about 3. (For example, 2.85 to 3.15) is preferable.

The X-ray diffraction peak obtained by X-ray diffraction and having 2θ of 35 ° or more and 36 ° or less is a ferrite crystal (hereinafter referred to as a main crystal) composed of oxides of Fe, Zn, Ni and Cu as main components. It may belong to the (220) plane. Further, the X-ray diffraction peak at 2θ of 29.5 ° or more and 30.5 ° or less belongs to the (311) plane of the main crystal. The inventors of the present invention have found that the main component composition satisfies the above-mentioned range and the X-ray diffraction peak intensity when 2θ is 35 ° or more and 36 ° or less is I ₁ , and the X-ray diffraction peak when 2θ is 29.5 ° or more and 30.5 ° or less. It has been found that when I ₂ / I ₁ is 0.350 or more and 0.380 or less when the strength is I ₂ , a ferrite sintered body having high specific resistance, magnetic permeability and Curie temperature can be obtained. In addition, although it is not clear why it is possible to achieve such excellent characteristics, it may be caused by the degree of solid solution of Zn in the main crystal.

Next, about the calculation method of mol% of the main component composition of the ferrite sintered body of the present embodiment, using an ICP (Inductively Coupled Plasma) emission spectroscopic analyzer or a fluorescent X-ray analyzer, Fe, Zn, Ni, By calculating the content of Cu, respectively converting to Fe ₂ O ₃ , ZnO, NiO, CuO, calculating the molar value from each molecular weight, and calculating the occupation ratio of each molar value in the total molar value Can be sought.

Next, a method for calculating I ₂ / I ₁ will be described. First, the ferrite sintered body is pulverized, and the pulverized powder is analyzed with an X-ray diffractometer (XRD) to obtain a diffraction chart. Then, the intensity of the X-ray diffraction peak when 2θ is 35 ° or more and 36 ° or less is I ₁ , the X-ray diffraction peak when 2θ is 39.5 ° or less is I _2, and I ₂ is divided by I ₁ to give I ₂ / I ₁ can be found.

  Next, a method for measuring specific resistance, magnetic permeability, and Curie temperature will be described. First, with respect to the magnetic permeability, a sample may be measured under the condition of a frequency of 100 kHz using an LCR meter. As a sample, for example, a ring-shaped toroidal core 1 made of a ferrite sintered body shown in FIG. 1A having an outer diameter of 13 mm, an inner diameter of 7 mm, and a thickness of 3 mm is used. A wire with a wire diameter of 0.2 mm wound around the entire circumference is used 10 times. Further, the Curie temperature can be obtained by a bridge circuit method using an LCR meter using a sample similar to that at the time of measuring the magnetic permeability.

  As for the specific resistance, for example, a plate-shaped sample having a diameter of 10 to 20 mm and a thickness of 0.5 to 2 mm is prepared, and an applied voltage of 1000 V and a temperature of 26 are measured using a super insulation resistance meter (TOA DSM-8103). It can be determined by measuring by the three-terminal method (JIS K6271; double ring electrode method) in a measurement environment of ° C and humidity of 36%.

  Further, in the ferrite sintered body of the present embodiment, it is preferable that the half width of the X-ray diffraction peak intensity when 2θ is 35 ° or more and 36 ° or less is 0.05 to 0.35. When the full width at half maximum of the X-ray diffraction peak intensity when 2θ is 35 ° or more and 36 ° or less is 0.05 or more and 0.35 or less, the amorphous crystal layer between the main crystals does not increase so much that the main crystal can be grown. Therefore, the mechanical characteristics can be improved without reducing the magnetic permeability. The half-value width is a half value of the width between diffraction peaks at 1/2 intensity of the maximum value of X-ray diffraction peak intensity when 2θ is 35 ° or more and 36 ° or less in the obtained diffraction chart.

Further, in the ferrite sintered body of the present embodiment, it is preferable that I ₃ / I ₁ is 0.140 or less when the X-ray diffraction peak intensity at 2θ of 42 ° or more and 43 ° or less is I ₃ . Here, the X-ray diffraction peak when 2θ is 42 ° or more and 43 ° or less belongs to the (400) plane of the main crystal. When the X-ray diffraction peak intensity when 2θ is 42 ° or more and 43 ° or less is I ₃ , when I ₃ / I ₁ is 0.140 or less, the uniaxial orientation is small, so that the mechanical characteristics can be improved. .

As described above, when the half width of the X-ray diffraction peak intensity when 2θ is 35 ° or more and 36 ° or less is 0.05 or more and 0.35 or less, or I ₃ / I ₁ is 0.140 or less, the mechanical characteristics are improved. In order to improve the yield, it is less likely to cause defects such as chipping due to barrel processing after firing in the manufacturing process, and damage due to stress applied during winding and electrode attachment and handling is reduced. Can be improved.

The ferrite sintered body of the present embodiment includes at least one of oxide and Bi oxide of Mo, the content of oxides of Mo with respect to the main component of 100 wt% at least 0.01 wt% calculated as MoO ₃ It is preferably 0.2% by mass or less, and the Bi oxide content is preferably 0.01% by mass or more and 0.2% by mass or less in terms of Bi ₂ O ₃ . The oxides of Mo and Bi can promote the grain growth of the main crystal. By setting the content within the above-described range, the magnetic permeability can be improved with almost no decrease in the Curie temperature. In particular, in order to further improve the magnetic permeability without substantially reducing the Curie temperature, the content of the Mo oxide is preferably 0.05% by mass or more and 0.1% by mass or less in terms of MoO _3. The content of the oxide is preferably 0.05% by mass or more and 0.1% by mass or less in terms of Bi ₂ O ₃ .

The ferrite sintered body of the present embodiment includes at least one of Mn oxide and Ti oxide, and the content of Mn oxide with respect to 100% by mass of the main component is 0.01% by mass or more in terms of MnO _2. It is preferably 0.3% by mass or less, and the content of Ti oxide is preferably 0.01% by mass or more and 0.2% by mass or less in terms of TiO ₂ . Since Mn and Ti can have a plurality of valences, oxygen defects in the main crystal are filled with surplus oxygen due to valence change during firing, so that oxygen defects in the main crystal are reduced and magnetic permeability is improved. Can do.

The ferrite sintered body of the present embodiment preferably contains a Zr oxide, and the content of the Zr oxide with respect to 100% by mass of the main component is 0.01% by mass or more and 0.2% by mass or less in terms of ZrO _2. It is. Thereby, specific resistance can be improved, without almost reducing magnetic permeability. In particular, in order to improve the specific resistance without substantially reducing the magnetic permeability, it is preferable that the content of the oxide of Zr is 0.01% by mass or more and 0.1% by mass or less in terms of ZrO ₂ .

In addition to the main components and oxides of Mo, Bi, Mn, Ti, and Zr, Si oxides and Ca oxides may be included. The specific resistance can also be improved by including this Si oxide or Ca oxide. When the oxide of Si or the oxide of Ca is included, the content with respect to 100% by mass of the main component is 0.4% by mass or less in total of the Si oxide converted to SiO ₂ and the Ca oxide converted to CaO. Is preferred.

Further, for the content of oxides of Mo, Bi, Mn, Ti and Zr, the content of Mo, Bi, Mn, Ti and Zr is determined using an ICP emission spectroscopic analyzer or a fluorescent X-ray analyzer, respectively in terms of _{MoO 3, Bi 2 O 3,} MnO 2, TiO 2 and ZrO _2, it may be calculated values for the main component of 100% by mass. The same applies to Si oxide and Ca oxide.

  Next, details of an example of the method for producing a ferrite sintered body according to the present embodiment will be described below.

First, as starting materials, Fe, Zn, Ni and Cu oxides or metal salts such as carbonates and nitrates that produce oxides by firing are prepared. At this time, as the average particle size, for example, when Fe is iron oxide (Fe ₂ O ₃ ), Zn is zinc oxide (ZnO), Ni is nickel oxide (NiO), and Cu is copper oxide (CuO), 0.5 It is not less than μm and not more than 5 μm.

Subsequently, a first raw material composed of a calcined powder composed of Fe ₂ O ₃ —ZnO—NiO and a _second raw material composed of a calcined powder composed of Fe ₂ O ₃ —CuO were prepared. In this case, iron oxide, zinc oxide and nickel oxide are weighed to a desired amount for the first raw material. Further, for the second raw material, iron oxide and copper oxide are weighed to a desired amount. Here, the amount of iron oxide added in the production of the first material and the second material is set such that the amount of iron oxide added in the production of the second material is, for example, equimolar to copper oxide, and the remaining amount is 1 is used to produce the raw material.

  Then, after the powders weighed for the first raw material and the second raw material are pulverized and mixed with separate ball mills, vibration mills, etc., the first raw material is produced in a reducing atmosphere at 750 ° C. for 2 hours or more. In the production of the second raw material, each calcined body is obtained by calcining at 650 ° C. for 2 hours or more in a reducing atmosphere.

Next, the first raw material and the second raw material made of the calcined powder are pulverized by putting the calcined bodies as the first raw material and the second raw material in separate ball mills or vibration mills, respectively. Get. At this time, the calcined body as the second raw material is pulverized so that the average particle diameter D ₅₀ is 0.7 μm or less. Then, the first raw material and the second raw material are weighed and mixed to a desired amount, and then re-calcined in the atmosphere under conditions of 600 ° C. to 700 ° C. and a temperature increase rate of 100 ° C./h. Thus, a calcined body synthesized into ferrite composed of oxides of Fe, Zn, Ni and Cu is obtained.

  Next, the calcined body obtained by recalcination is put in a ball mill or a vibration mill and pulverized, and a predetermined amount of binder or the like is added to form a slurry, and this slurry is sprayed using a spray dryer and granulated. By doing so, spherical granules are obtained. And it press-molds using the obtained spherical granule, and obtains the molded object of a predetermined shape. Then, after performing a degreasing process in the range of 400-800 degreeC in a degreasing furnace, a molded object is made into a degreased body, Then, this is hold | maintained at the highest temperature of 1000-1200 degreeC for 2 to 5 hours, and is baked. Thus, the ferrite sintered body of the present embodiment can be obtained.

The ferrite sintered body obtained by the above-described method is obtained by X-ray diffraction. The X-ray diffraction peak intensity when 2θ is 35 ° or more and 36 ° or less is I ₁ and X when 2θ is 29.5 ° or more and 30.5 ° or less is X. When the line diffraction peak intensity is I ₂ , I ₂ / I ₁ is 0.350 or more and 0.380 or less, and a ferrite sintered body having high specific resistance, magnetic permeability, and Curie temperature is obtained.

On the other hand, I ₂ / I ₁ exceeds 0.380 because the Zn oxide content is too small, the average particle size of the second raw material is too large, or the temperature during recalcination is too low. Or when the particle size after pulverization is too large, or the rate of temperature increase during recalcination is too fast, and I ₂ / I ₁ is less than 0.350. This is when there is too much content of oxide. Based on these findings, the present inventors believe that the degree of solid solution of Zn in the main crystal is caused by whether or not the above-described excellent characteristics can be obtained. In order to increase the degree of Zn solid solution, a first raw material composed of a calcined powder composed of Fe ₂ O ₃ —ZnO—NiO and a calcined powder composed of Fe ₂ O ₃ —CuO The divisional calcination of further calcination using the second raw material is adopted.

Moreover, in the pulverization of the calcined body obtained by recalcination, it is preferable to pulverize so that the average particle diameter D ₅₀ is 0.8 μm or less. Thereby, I ₃ / I ₁ can be made 0.140 or less. In order to reduce the average particle diameter D ₅₀ , the pulverization time must be lengthened. Since the pulverization for a long time increases the possibility of mixing from the balls used for pulverization, the average particle diameter D ₅₀ is increased. The lower limit is preferably about 0.5 μm. In addition, it is preferable that the temperature increase rate in firing is 100 ° C. or more and 300 ° C. or less. Thereby, the half value width of the X-ray diffraction peak intensity when 2θ is 35 ° or more and 36 ° or less can be set to 0.05 or more and 0.35 or less.

In order to contain oxides of Mo, Bi, Mn, Ti and Zr, for example, molybdenum oxide (MoO ₃ ), bismuth oxide (Bi ₂ O ₃ ), manganese oxide (MnO ₂ ), titanium oxide (TiO ₂ ). ) And zirconium oxide (ZrO ₂ ) may be prepared and added during pulverization after recalcination. As for Ca oxide and Si oxide, calcium oxide (CaO) or silicon oxide (SiO ₂ ) may be prepared and added during pulverization after recalcination.

  Examples of the present invention will be specifically described below, but the present invention is not limited to these examples. Examples of the sintered ferrite body of the present invention are shown below.

  Ferrite sintered bodies with various changes in the main component composition and production conditions were produced, and the permeability and Curie temperature were confirmed. A method for manufacturing the sample is described below. First, iron oxide, zinc oxide, nickel oxide and copper oxide powders having an average particle size of 1 μm were prepared. And about zinc oxide, nickel oxide, and copper oxide, it measured so that it might become a composition shown in Table 1. Next, the iron oxide was weighed so that the second raw material was equimolar with copper oxide and the balance was for the first raw material.

  Each of the first raw material iron oxide, zinc oxide and nickel oxide weighed and pulverized and mixed with a ball mill, calcined at 750 ° C. for 2 hours in a reducing atmosphere, and the obtained calcined body was pulverized. A first raw material was obtained. Further, after iron oxide and copper oxide for the second raw material are pulverized and mixed with a ball mill, the second raw material is obtained by calcination at 650 ° C. for 2 hours in a reducing atmosphere and pulverizing the obtained calcined body. Obtained. In addition, about the 2nd raw material, it grind | pulverized so that it might become the average particle diameter shown in Table 1.

  Next, after the first raw material and the second raw material are mixed, they are re-calcined in the atmosphere at the heating rate and temperature conditions shown in Table 1, and then pulverized under the same conditions using a ball mill. A certain amount of binder was added to form a slurry, and the slurry was sprayed and granulated using a spray dryer to obtain spherical granules. Next, the molded product having the shape of the toroidal core 1 shown in FIG. 1 was obtained by press molding using the obtained spherical granules. Thereafter, the molded body is held at a maximum temperature of 600 ° C. in a degreasing furnace for 5 hours to be degreased to obtain a degreased body, and this is held in a firing furnace at a maximum temperature of 1100 ° C. for 2 hours in an air atmosphere. Baked. Next, this sintered body was ground to obtain a toroidal sample No. 1 having an outer diameter of 13 mm, an inner diameter of 7 mm, and a thickness of 3 mm. 2 to 28 ferrite sintered bodies were obtained.

  Moreover, using the raw material divided | segmented and calcined as mentioned above (henceforth divided calcining), the powder of iron oxide, zinc oxide, nickel oxide, and copper oxide whose average particle diameter is 1 micrometer is used. Sample No. 1 was prepared by the same production method as described above, except that it was weighed so as to have the composition shown in Table 1 and calcined at the temperature rise rate and temperature conditions shown in Table 1. 1 was obtained. In Table 1, the presence or absence of divided calcination is described.

Then, to determine the I ₂ / I ₁ from the diffraction chart obtained by XRD for each sample. Further, a coated copper wire having a wire diameter of 0.2 mm was wound 10 times around the entire circumference of the winding portion 10a of each sample, and the magnetic permeability at a frequency of 100 kHz was measured using an LCR meter. Further, the Curie temperature was obtained by a bridge circuit method using an LCR meter, using the same sample as that at the time of measuring the magnetic permeability.

For each sample, the amounts of Fe, Zn, Ni and Cu metal elements were determined using a fluorescent X-ray analyzer and converted to Fe ₂ O ₃ , ZnO, NiO and CuO, respectively, and the molecular weight was calculated from the respective molecular weights. The values were calculated, and the occupation ratio of each molar value in the total molar value was calculated and shown in Table 1.

From Table 1, sample No. which was not subjected to divided calcination For No. ₁ , the value of I ₂ / I ₁ was 0.400, and the magnetic permeability was as low as 2290. In addition, although the sample was divided and calcined, the second raw material after pulverization had an average particle diameter (D ₅₀ ) of 0.8 μm. 5. Sample No. 5 having a re-calcination temperature of 550 ° C. 6. Sample No. having a re-calcination temperature of 750 ° C. 9, Sample No. with a heating rate of 120 ° C./h during recalcination For 10, the value of I ₂ / I ₁ was outside the range of 0.350 to 0.380, and the magnetic permeability was less than 3,000. This is because the average particle size of the second raw material is too large, the temperature during recalcination is too low, the temperature during recalcination is too high, and the particle size after pulverization is large, the temperature rise during recalcination It is considered that the magnetic permeability was low because there was little solid solution of Zn in the main crystal due to factors such as the speed being too fast.

Of the main component composition of 100 mol%, Fe is 49 mol% or more and 50 mol% or less in terms of Fe ₂ O ₃ , Zn is 32 mol% or more and 34 mol% or less in terms of ZnO, and Ni is 10 mol% in terms of NiO. No. 12.5 mol% or less, Cu not satisfying any of the ranges of 4 mol% or more and 8 mol% or less in terms of CuO. For 13, 16, 17, 22, 23, 25, 26 and 28, the permeability was less than 3000 or the Curie temperature was less than 90.

In contrast, among the main component composition 100 mol%, Fe and Fe ₂ O ₃ 50 mol% 49 mol% or more in terms of less, or more 32 mol% calculated as ZnO Zn 34 mol% or less, the Ni in terms of NiO 10 The X-ray diffraction peak intensity at 2θ of 35 ° or more and 36 ° or less obtained by X-ray diffraction is expressed as I ₁ , 2θ. sample No. There when the X-ray diffraction peak intensity definitive to 29.5 ° than 30.5 ° or less was I _2, I ₂ / I ₁ is 0.350 or more 0.380 or less For 2-4, 7, 8, 11, 12, 14, 15, 18-21, 24 and 27, the magnetic permeability is 3000 or higher, and the Curie temperature (Tc) is 90 ° C or higher. It was also found to be a ferrite sintered body with a high Curie temperature.

Sample No. About 2-4,7,8,11,12,14,15,18-21,24 and 27, using the same granule as produced in Example 1, φ is 10-20 mm and thickness is 0.5-2 mm A three-terminal method (JIS K6271; double ring) in a measurement environment with an applied voltage of 1000V, temperature of 26 ° C, and humidity of 36% using a super insulation resistance meter (TOA DSM-8103) When measured by the electrode method), all values were 10 ⁹ Ω · m or more. As a result, it was found that the ferrite sintered body of this embodiment is a ferrite sintered body having a high specific resistance, magnetic permeability, and Curie temperature.

  Ferrite sintered bodies with various changes in the heating rate during firing were prepared, and the permeability and mechanical properties were confirmed. Note that the manufacturing method other than setting the temperature rising rate during firing to the temperature shown in Table 2 for each sample was the same as that of Sample No. 1 of Example 1. Same as 11. The heating rate during firing in Example 1 was 100 ° C. 30 is Sample No. Same as 11.

  As for the half-value width, Table 2 shows half the width between diffraction peaks at 1/2 intensity of the maximum value of X-ray diffraction peak intensity when 2θ is 35 ° or more and 36 ° or less. As for mechanical properties, the three-point bending strength was measured in accordance with JIS R1601-2008. Further, the magnetic permeability and the mol% of the main component were determined by the same method as in Example 1. The results are shown in Table 2.

  From Table 2, it was found that the mechanical characteristics can be improved without lowering the magnetic permeability when the half width of the X-ray diffraction peak intensity when 2θ is 35 ° or more and 36 ° or less is 0.05 or more and 0.35 or less. .

The average particle diameter D ₅₀ in the grinding after re-calcination to produce various modified ferrite sintered body was performed to confirm the relationship between permeability and mechanical properties. The average particle diameter manufacturing method other than the D ₅₀ to the size shown in per Table 3 in each sample after re-calcination, the sample of Example 1 No. Same as 11. The average particle diameter D ₅₀ after recalcination in Example 1 is 0.80 μm. 40 is sample No. Same as 11. Sample No. 42 and sample no. The only difference from 43 is the rate of temperature rise during firing.

For calm particle size D ₅₀ after re-calcination was measured by a laser diffraction scattering method using a micro-track machine (manufactured by Nikkiso Co. MT3300EXII). Further, I ₃ / I ₁ was determined from the diffraction chart obtained by XRD for each sample. Furthermore, the value of 3-point bending strength was determined by the same method as in Example 2. Further, the magnetic permeability and the mol% of the main component were determined by the same method as in Example 1. The results are shown in Table 3.

From Table 3, it was found that when I ₃ / I ₁ is 0.140 or less, the mechanical characteristics can be improved. In Examples 2 and 3, the mechanical characteristics were evaluated at a three-point bending strength. However, it can also be evaluated by measuring the hardness in accordance with JIS1610-2003. Sample No. 3 having a three-point bending strength of 150 MPa. Sample No. 40 had a hardness of 7.5 GPa and a three-point bending strength of 170 MPa. The hardness of 44 was 8.2 GPa.

  Next, sample no. A ferrite sintered body containing the same composition as in No. 11 with various addition amounts of Mo oxide and Bi oxide was prepared, and the permeability and Curie temperature were confirmed. A sample was prepared in the same manner as in Example 1 except that molybdenum oxide and bismuth oxide having the contents shown in Table 2 were added during pulverization after recalcination. Further, the magnetic permeability and the Curie temperature were measured by the same method as in Example 1.

Further, the mol% ratio of the main component was calculated by the same method as in Example 1. Further, the Mo and Bi, seeking amount of metal element in terms of MoO _3, Bi ₂ O ₃ using a fluorescent X-ray analyzer, the calculated value of the mass relative to the main component of 100% by mass are shown in Table 4.

From Table 4, with respect to 100% by mass of the main component, the Mo oxide content is 0.01 to 0.2% by mass in terms of MoO ₃ or the Bi oxide content is 0.01% by mass in terms of Bi ₂ O _3. It has been found that when the content is 0.2% by mass or less, the magnetic permeability can be improved without substantially reducing the Curie temperature. In particular, sample no. Nos. 49 and 50 obtained high magnetic permeability, and it was found that the Mo oxide content with respect to 100% by mass of the main component was suitably 0.05% by mass or more and 0.1% by mass or less in terms of MoO ₃ . For Bi, sample no. The results of high magnetic permeability were obtained in 56 and 57, and it was found that the Bi oxide content relative to 100% by mass of the main component was suitably 0.05% by mass or more and 0.1% by mass or less in terms of Bi ₂ O ₃ .

  Next, sample no. Ferrite sintered bodies were prepared by adding various amounts of Mn oxide and Ti oxide to the same composition as 50, and the permeability and Curie temperature were confirmed. In addition, the sample was produced by the method similar to Example 2 except having added the manganese oxide and titanium oxide used as content shown in Table 3 at the time of the grinding | pulverization after recalcination. Further, the magnetic permeability and the Curie temperature were measured by the same method as in Example 1.

Further, the mol% ratio of the main component was calculated by the same method as in Example 1. Further, Mo, Mn, for Ti, seeking amount of metal element in terms of MoO _3, MnO _2, TiO ₂ using a fluorescent X-ray analyzer, the calculated value of the mass relative to the main component of 100% by mass shown in Table 5 It was. In all samples, the oxide of Mo is 0.1% by mass in terms of MoO ₃ , so it is not listed in Table 5.

From Table 5, with respect to 100% by mass of the main component, the content of the Mn oxide is 0.01% by mass to 0.3% by mass in terms of MnO ₂ , and the content of the Ti oxide is 0.01% by mass to 0.2% in terms of TiO _2. It was found that the magnetic permeability can be improved with almost no decrease in Curie temperature by being less than or equal to mass%.

  Next, sample no. Ferrite sintered bodies containing various changes in the amount of Zr oxide added in the same composition as in 67 were prepared, and the magnetic permeability and specific resistance were confirmed. In addition, the sample was produced by the method similar to Example 3 except having added the zirconium oxide used as content shown in Table 6 at the time of the grinding | pulverization after recalcination. Further, the magnetic permeability and specific resistance were measured by the same method as in Example 1.

Further, the mol% ratio of the main component was calculated by the same method as in Example 1. Further, Mo, Mn, for Zr, seeking amount of metal element in terms of MoO _3, MnO _2, ZrO ₂ using a fluorescent X-ray analyzer, shows the calculated value of the mass relative to the main component of 100% by mass Table 6 It was. In all samples, the oxide of Mo was 0.1% by mass in terms of MoO ₃ , and the oxide of Mn was 0.2% by mass in terms of MnO ₂ , so that it is not shown in Table 6.

From Table 6, when the content of the oxide of Zr is 0.01% by mass or more and 0.2% by mass or less in terms of ZrO ₂ with respect to 100% by mass of the main component, the specific resistance can be improved without substantially reducing the magnetic permeability. I was able to plan.

  And since the ferrite sintered compact of this embodiment is a thing with high specific resistance, magnetic permeability, and Curie temperature, the ferrite core which consists of a ferrite sintered compact of this embodiment is independent, or a metal wire is used for a ferrite core. It has been found that it is suitable for use as a wound coil component. In particular, various devices in recent years have become capable of LAN connection, and coil components used for pulse transformers in this LAN interface section are required to have excellent characteristics, but the coil components of this embodiment are required characteristics. Therefore, it was found that the coil component is suitable for a pulse transformer.

1: Toroidal core 1a: Winding part 2: Bobbin core 2a: Winding part

Claims (9)

Fe, Zn, as main components ferrite comprising an oxide of Ni and Cu, among the composition 100 mol% of the main component, Fe and Fe ₂ O ₃ 50 mol% 49 mol% or more in terms of less, ZnO converted Zn A ferrite sintered body containing 32 mol% or more and 34 mol% or less, Ni containing 10 mol% or more and 12.5 mol% or less in terms of NiO, and Cu containing 4 mol% or more and 8 mol% or less in terms of CuO, When the X-ray diffraction peak intensity when 2θ is 35 ° or more and 36 ° or less obtained by line diffraction is I ₁ , and the X-ray diffraction peak intensity when 2θ is 29.5 ° or more and 30.5 ° or less is I ₂ , ₂ / I ₁ is 0.350 or more and 0.380 or less, and the ferrite sintered compact characterized by the above-mentioned. 2. The ferrite sintered body according to claim 1, wherein the half width of the X-ray diffraction peak intensity when 2θ is 35 ° or more and 36 ° or less is 0.05 or more and 0.35 or less. _3. The ferrite material according to claim ₁ , wherein I ₃ / I ₁ is 0.140 or less, where I ₃ is an X-ray diffraction peak intensity at 2θ of 42 ° or more and 43 ° or less. Sintered body. Including at least one of an oxide of Mo and an oxide of Bi, the content of the oxide of Mo with respect to 100% by mass of the main component is 0.01% by mass or more and 0.2% by mass or less in terms of MoO ₃ ; ferrite sintered body according to any one of claims 1 to 3 content of the oxide of Bi is equal to or less than 0.2 mass% to 0.01 mass% in terms of Bi ₂ O ₃ . It contains at least one of Mn oxide and Ti oxide, and the content of Mn oxide with respect to 100% by mass of the main component is 0.01% by mass to 0.3% by mass in terms of MnO ₂ , The ferrite sintered body according to any one of claims 1 to 4, wherein the oxide content is 0.01% by mass or more and 0.2% by mass or less in terms of TiO ₂ . The content of the Zr oxide with respect to 100% by mass of the main component is 0.01% by mass or more and 0.2% by mass or less in terms of ZrO ₂ , including a Zr oxide. Item 6. The ferrite sintered body according to any one of Items 5 to 6. A ferrite core comprising the ferrite sintered body according to any one of claims 1 to 6. A coil component comprising a ferrite core according to claim 7 wound around a metal wire. The coil component according to claim 8, wherein the coil component is used in a pulse transformer.

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