TW202402709A - Ni-Zn-Cu-based ferrite powder, sintered body, and ferrite sheet - Google Patents

Abstract

The purpose of the present invention is to provide a Ni-Zn-Cu-based ferrite powder that can be sintered at a low temperature of, for example, 860 DEG C. The present invention relates to: a Ni-Zn-Cu ferrite powder characterized by containing at most 49 mol% of Fe2O3, 5-25 mol% of NiO, 15-40 mol% of ZnO, 5-15 mol% of CuO, and 0-3 mol% of CoO, the Ni-Zn-Cu ferrite powder having a crystallite size of 180 nm or less; and a sintered body or a ferrite sheet using said Ni-Zn-Cu-based ferrite powder.

Description

Ni-Zn-Cu series ferrous iron powder, sintered body, ferrous iron flakes

The present invention relates to a Ni-Zn-Cu-based ferrous iron material, which is a fertile iron powder that can be sintered at low temperatures. The present invention also relates to a sintered body and ferrous iron flakes using the aforementioned fertile iron powder. .

In recent years, with the development of smaller and lighter electronic equipment for home use and industrial use, there has been an increasing demand for electronic components used in the various electronic equipment mentioned above to be smaller, more efficient, and more frequent.

For example, inductors used in electronic circuits of electronic equipment are wound types in which copper wire with insulation coating is wound around a magnetic core or an air-core bobbin to form a coil. Sintered type laminated chip inductors have been put into practical use.

This multilayer chip inductor is manufactured through the following manufacturing steps. That is, a paste containing ferrous iron powder is formed into a sheet shape to form a green sheet, and a paste containing an electrode material such as Ag, Ag-Pd, etc. is used and printed on the green sheet. After forming conductive patterns on green sheets, they are laminated and sintered at a specified temperature to form external electrodes.

However, in the manufacturing process of the multilayer chip inductor as described above, since the electrode material and the laminated body of the ferrite are fired simultaneously, the electrode material such as Ag, Ag-Pd, etc. Interfacial reaction (interdiffusion) may cause problems such as deterioration of the original properties of ferrous iron. In order to avoid this problem, it is considered necessary to perform firing at a low temperature such as approximately 900°C or lower.

However, when firing is performed at a temperature of 900° C. or lower, it is difficult to obtain a Ni-based fertile iron sintered body that is excellent in electromagnetic properties such as magnetic permeability as a magnetic body for multilayer chip inductors.

So far, several technologies have been proposed for Ni-Zn-Cu-based fertile iron powders that can be sintered even at low temperatures. For example, there is a method of adding borosilicate glass as a sintering aid to generate a liquid phase during sintering to promote the growth of ferrous iron particles (Patent Document 1); other methods of adding glass components are also There is a method of adding a glass component composed of SiO ₂ , B ₂ O ₃ , and Na ₂ O to form liquid phase sintering to promote the growth of fat iron particles (Patent Document 2). In order to reduce the magnetic permeability of PbO and ferrous iron, which have a large environmental load, glass components that do not contain Na (which will have adverse effects on other electronic devices) are added to form liquid phase sintering to promote ferrous iron. Method for growing particles (Patent Document 3). Furthermore, for RFID applications, a method is proposed to achieve high magnetic permeability by controlling the half-maximum width of the XRD diffraction peak of the crystal phase of Ni-Zn-Cu-based fertilized iron powder (Patent Document 4). [Prior art documents] [Patent documents]

[Patent Document 1] Japanese Patent Application Laid-Open No. 5-326241 [Patent Document 2] Japanese Patent Application Publication No. 2000-208316 [Patent Document 3] Japanese Patent Application Publication No. 2007-99539 [Patent Document 4] Japanese Patent Application Publication No. 2005-64468

[Problem to be solved by the invention]

Patent Documents 1 to 3 all use a method of adding a glass component to form liquid phase sintering to promote the growth of ferrous iron particles. However, the addition amount of these additives is very small, so it is difficult to disperse them uniformly, thereby promoting the uneven growth of fat iron particles. Furthermore, in Patent Document 4, no sintering aid is added, but sintering needs to be performed at a high temperature of 1060° C. or higher, so sintering at low temperatures is not considered.

Therefore, in order to solve the above-mentioned problems of the prior art, an object of the present invention is to provide a Ni-Zn-Cu based fertilized iron powder that can be sintered at low temperature. [Means to solve the problem]

The aforementioned technical problems can be achieved by the present invention as described below.

That is, the present invention is a Ni-Zn-Cu-based fertilized iron powder, which is characterized by containing less than 49 mol% Fe ₂ O ₃ , 5 to 25 mol% NiO, 15 to 40 mol% ZnO, and 5 to 15 mol% CuO. And 0~3mol% CoO, the crystal grain size is 180nm or less (Invention 1).

Moreover, the present invention is the Ni-Zn-Cu-based fertilized iron powder as described in Invention 1, wherein the distortion is 0.330 or less (Invention 2).

Furthermore, the present invention is the Ni-Zn-Cu-based fertilized iron powder according to the present invention 1 or 2, wherein the sintering density is 5.00 g/cm ³ or more when fired at 860° C. in the air (the present invention 3).

Furthermore, the present invention is a sintered body using the Ni-Zn-Cu-based fertilized iron powder described in any one of Inventions 1 to 3 (Invention 4).

Furthermore, the present invention is a ferrous iron flake using the Ni-Zn-Cu-based ferrous iron powder described in any one of Inventions 1 to 3 (Invention 5). [Effects of the invention]

Since the Ni-Zn-Cu-based ferrous iron powder related to the present invention has a small grain size, a fertile iron sintered body with a high sintering density can be obtained even if it is sintered at a low temperature. In addition, the Ni-Zn-Cu based fertilized iron powder related to the present invention can be sintered at a low temperature of, for example, 860°C. Therefore, when used in a multilayer inductor in which Ag and magnetic powder are fired at the same time, it is possible to suppress The diffusion of Ag, which has a low melting point, can be expected to improve the performance of the inductor.

[The best way to implement the invention]

The Ni-Zn-Cu based fertilized iron powder related to the present invention will be described.

The Ni-Zn-Cu based fertilized iron powder according to the present invention contains Fe, Ni, Zn and Cu as constituent metal elements, and also contains Co as necessary. When the constituent metal elements are converted into Fe ₂ O ₃ , NiO, ZnO, CuO and CoO respectively, based on the total of Fe ₂ O ₃ , NiO, ZnO, CuO and CoO (100%), it contains 49 mol% or less of Fe ₂ O ₃ , 5~25mol% NiO, 15~40mol% ZnO, 5~15mol% CuO and 0~3mol% CoO.

The Fe content of the Ni-Zn-Cu based fertilized iron powder related to the present invention is 49 mol% or less in terms of Fe ₂ O ₃ . If the Fe content exceeds 49 mol%, the sinterability will be significantly reduced. The content of Fe is preferably 48.9 mol% or less, and more preferably 48.8 mol% or less. The lower limit is about 45 mol%.

The Ni content of the Ni-Zn-Cu series fertilized iron powder related to the present invention is 5 to 25 mol% when converted to NiO. If the Ni content is less than 5 mol%, μ’ will decrease, which is undesirable. In addition, lowering the curie temperature is undesirable because the usable temperature range is limited. Even when the Ni content exceeds 25 mol%, μ' decreases, which is unfavorable. The Ni content is preferably 6 to 24.9 mol%, and more preferably 7 to 24.8 mol%.

The Zn content of the Ni-Zn-Cu series fertilized iron powder related to the present invention is 15 to 40 mol% when converted to ZnO. If the Zn content is less than 15 mol%, μ’ will decrease, which is undesirable. In addition, lowering the Curie temperature is undesirable because the usable temperature range is limited. Even when the Zn content exceeds 40 mol%, μ' decreases, which is unfavorable. The Zn content is preferably 18~38 mol%, and more preferably 20~35 mol%

The Cu content of the Ni-Zn-Cu series fertilized iron powder related to the present invention is 5 to 15 mol% when converted to CuO. If the Cu content is less than 5 mol%, the sinterability will decrease, making it difficult to produce a sintered body at low temperature. If the Cu content exceeds 15 mol%, μ’ will decrease, which is undesirable. The content of Cu is preferably 6 to 14 mol%, and more preferably 7 to 13 mol%.

The Ni-Zn-Cu based fertilized iron powder related to the present invention may also contain Co. When converted to CoO, the Co content is 0~3 mol%. In the present invention, by adding Co to fat iron, Snoek's limit line is shifted to the high-frequency side, so that the imaginary part μ", which is the complex permeability in the high-frequency domain, can be improved. Q (μ'/μ") of ferrite core which is the ratio of real part μ'. However, if the Co content exceeds 3 mol% in terms of CoO, the magnetic permeability will decrease and the Q of the fat core will also tend to decrease. The Co content is preferably 0 to 2.9 mol%, more preferably 0 to 2.8 mol%, and particularly preferably 0.1 to 2.8 mol%.

The Ni-Zn-Cu series fertile iron powder related to the present invention has a grain size of 180 nm or less. If the crystal grain size exceeds 180 nm, particle growth in the magnetic powder stage will be accelerated, so when the sintered body or green sheet is fired, the sintering properties will be reduced, making it impossible to sinter at low temperatures. Furthermore, it is preferably 175nm or less, more preferably 170nm or less. The lower limit is about 100nm. Furthermore, the crystal grain size can be obtained by the method described in the Examples below. In particular, the crystal grain size can be adjusted within the above range by adjusting the BET specific surface area of Fe ₂ O ₃ as the Fe raw material described later.

The Ni-Zn-Cu series fertilized iron powder related to the present invention preferably has a crystal distortion of 0.330 or less. If the distortion exceeds 0.330, μ’ will decrease, which is not good. Furthermore, it is preferably 0.325 or less, more preferably 0.320 or less. The lower limit is around 0.100. Furthermore, the Ni-Zn-Cu series ferrous iron powder related to the present invention is preferably spinel fertilized iron single phase. Furthermore, the distortion system of the crystal grains can be obtained by the method of the embodiments described below. The distortion of the grains can be adjusted by the pre-sintering temperature and crushing strength of the ferrous iron powder.

The Ni-Zn-Cu based fertilized iron powder related to the present invention may contain various elements at impurity levels in addition to the above-mentioned elements within a range that does not affect its characteristics. It is generally known that the addition of Bi is effective in lowering the sintering temperature of ferrous iron. However, if the dispersion state of Bi is uneven, uneven growth of particles will be promoted during firing, so it is not good to actively add Bi, and it is better not to contain Bi (0 ppm).

The Ni-Zn-Cu-based fertilized iron powder related to the present invention may also contain Si as an unavoidable impurity, and the upper limit is 500 ppm in terms of SiO ₂ conversion. It is preferable that it does not contain Sn etc. (0ppm).

The Ni-Zn-Cu-based ferrous iron powder related to the present invention is made by mixing the oxides, carbonates, hydroxides, oxalates, etc. of each element constituting the fertilized iron in a specified composition ratio by conventional methods. The raw materials are used to obtain a raw material mixture, or each element is precipitated in an aqueous solution to obtain a co-precipitate. It can be obtained by precalcining in the atmosphere at a temperature ranging from 650 to 950°C for 1 to 20 hours, and then pulverizing it. The preferred temperature range for pre-calcining is 700~940°C. Furthermore, when an electrode material such as Ag or Ag-Pd is fired simultaneously with a laminate of ferrous iron, the sintering temperature is preferably 900°C or lower, so the pre-sintering temperature is set to a lower temperature (less than 900°C). 900℃) is preferred.

In the present invention, the BET specific surface area of Fe ₂ O ₃ as the Fe raw material is preferably 6.0 m ² /g or more. If the BET specific surface area of Fe ₂ O ₃ is less than 6.0 m ² /g, the mixing of each raw material will become uneven, so the sinterability of the ferromagnetic powder will be reduced, and high temperature will not be obtained during low-temperature sintering. Sintered density. The BET specific surface area of Fe ₂ O ₃ is preferably 6.5 to 40.0 m ² /g, and more preferably 7.0 to 30.0 m ² /g. Furthermore, for example, the BET specific surface area of Fe ₂ O ₃ can be controlled by adjusting the particle size in the synthesis stage of Fe ₂ O ₃ , adjusting the sintering temperature, and adjusting the crushing intensity.

Furthermore, in the present invention, since no sintering aid is added during the production of the Ni-Zn-Cu-based fertile iron powder, uneven growth of particles can be suppressed.

Next, the Ni-Zn-Cu based fertilized iron sintered body related to the present invention will be described.

The sintering density of the fat grain iron sintered body is preferably one that can obtain a high sintering density even when sintering at a low temperature, such as about 860°C, and is preferably 5.00 g/cm ³ or more. good. If the sintering density is less than 5.00 g/cm ³ , sufficient electromagnetic characteristics cannot be obtained, and the mechanical strength of the sintered body will be low, which is undesirable. The upper limit of sintered density is about 5.40g/ ^cm3 .

The Ni-Zn-Cu based fertilizer granular iron sintered body related to the present invention is made by using a mold to pressurize the Ni-Zn-Cu based fertilizer granules related to the present invention at a pressure of 0.3~3.0×10 ⁴ t/m ² Iron powder (i.e., the so-called powder press molding method) is used to obtain a molded body, or green sheets containing the Ni-Zn-Cu-based ferrous iron powder related to the present invention are laminated (i.e., the so-called green body sheet method), and the resulting laminated body is sintered at 840 to 1050° C. for 1 to 20 hours (preferably 1 to 10 hours). As the molding method, a known method can be used, but the above-mentioned powder press molding method or green sheet method is preferred.

If the sintering temperature is less than 840°C, the sintering density will decrease, so sufficient electromagnetic characteristics cannot be obtained, and the mechanical strength of the sintered body will also decrease. When the sintering temperature exceeds 1050° C., the sintered body becomes easily deformed, making it difficult to obtain a sintered body of a desired shape. In addition, for example, in the case of laminated chip inductors, since the laminate of electrode materials such as Ag, Ag-Pd and ferrous iron is fired at the same time, the interfacial reaction (mutual diffusion) between the electrodes and ferrous iron may cause the electrode to Broken wires and deterioration of the original characteristics of iron particles. The best sintering temperature is 860~1040℃. Furthermore, when the above-mentioned electrode material such as Ag, Ag-Pd, and a laminate of fertilized iron particles are fired simultaneously, the sintering temperature is preferably 900°C or lower. Of course, if the Ni-Zn-Cu based fertilized particles of the present invention When iron powder is not fired simultaneously with electrode materials such as Ag and Ag-Pd, the upper limit of the sintering temperature can be set to 1050°C.

The Ni-Zn-Cu-based fertile iron sintered body related to the present invention can be made into a specified shape according to the application, and can thereby be used as a magnetic material for multilayer chip inductors, inductance components, and other electronic components.

Next, the green sheet in the present invention will be described.

The so-called green sheet is made by mixing the above-mentioned Ni-Zn-Cu-based fertilized iron powder with a binding material, a plasticizer, a solvent, etc. to form a coating, and then using a blade coater or the like to form a film of the coating A thin sheet that is dried to a thickness of several μm to hundreds of μm. After stacking the sheets, they are pressurized to form a laminated body. Depending on the application, the laminated body can be sintered at a specified temperature to obtain laminated chip inductors, inductance components, and other electronic components.

The green sheet in the present invention contains 2 to 20 parts by weight of a binding material and 0.5 to 15 parts by weight of a plasticizer relative to 100 parts by weight of the Ni-Zn-Cu series fertilized iron powder related to the present invention. Preferably, it contains 4 to 15 parts by weight of adhesive material and 1 to 10 parts by weight of plasticizer. In addition, the solvent may remain due to insufficient drying after film formation. Furthermore, well-known additives such as viscosity adjusters may be added as necessary.

Types of adhesive materials include polyvinyl butyral, polyacrylate, polymethyl methacrylate, vinyl chloride, polymethacrylate, vinyl cellulose, rosin acid resin, etc. A preferred adhesive material is polyvinyl butyral.

If the amount of the adhesive material is less than 2 parts by weight, the green sheet will become brittle, and in order to have strength, the content does not need to exceed 20 parts by weight.

Types of plasticizers include benzyl-n-butyl phthalate, butyl butyl phthalate glycolate, dibutyl phthalate, dimethyl phthalate, and polyethylene glycol. Ester, phthalate ester, butyl stearate, methyl acetate, etc.

If the plasticizer is less than 0.5 parts by weight, the green sheet will become hard and cracks will easily occur. If the plasticizer exceeds 15 parts by weight, the green sheet will become soft and difficult to handle.

When producing the green sheet in the present invention, 15 to 150 parts by weight of the solvent is used based on 100 parts by weight of the Ni-Zn-Cu based fertilized iron powder. When the solvent is outside the above range, a uniform green sheet cannot be obtained. Therefore, multilayer chip inductors, inductance elements, and other electronic components obtained by sintering the green sheets tend to have uneven characteristics.

Types of solvents include acetone, benzene, butanol, ethanol, methyl ethyl ketone, toluene, propanol, isopropyl alcohol, n-butyl acetate, 3methyl-3methoxy-1butanol, etc.

The build-up pressure is preferably 0.2×10 ⁴ ~0.6×10 ⁴ t/m ² .

Next, the fat iron sheet related to the present invention will be described.

In the present invention, a Ni-Zn-Cu based fertilized iron sintered body is used in a plate shape to produce a fertilized iron sheet.

The thickness of the plate-shaped fertilized iron sintered body in the present invention is preferably 0.01 to 1 mm. Preferably, it is 0.02~1mm, and more preferably, it is 0.03~0.5 mm.

In the fertilized iron sheet according to the present invention, an adhesive layer may be provided on at least one surface of the fertile iron sintered plate. The thickness of the adhesive layer is preferably 0.001~0.1mm.

In the fertilized iron sheet according to the present invention, a protective layer may be provided on at least one surface of the fertile iron sintered plate. The thickness of the protective layer is preferably 0.001~0.1mm.

Examples of the adhesive layer in the present invention include double-sided adhesive tapes. The double-sided adhesive tape is not particularly limited, and a well-known double-sided adhesive tape can be used. Furthermore, as the adhesive layer, an adhesive layer, a flexible and stretchable film or sheet, an adhesive layer, and a release sheet may be laminated in this order on one side of the fertile iron sintered plate.

By providing the protective layer in the present invention, it is possible to improve the reliability and durability against powder loss when dividing the fertile iron sintered plate. The protective layer is not particularly limited as long as it is a resin that does not break and stretches when the ferrite sheet is bent, and examples thereof include PET films.

The fat iron sheet related to the present invention may have at least one groove preliminarily provided on at least one surface of the fat iron sintered plate in order to adhere closely to the curved portion and prevent cracking during use. As a starting point, a fertile iron sintered plate that can be divided is constructed. The aforementioned grooves may be formed continuously or intermittently. Furthermore, by forming a plurality of minute recesses, they may be used instead of the grooves. The groove should be U-shaped or V-shaped in cross-section.

In order for the fertilized iron sheet related to the present invention to adhere closely to the curved portion and to prevent cracking during use, it is preferable to divide the fertile iron sintered plate into small pieces in advance. For example, the ferrous iron sintered board is divided using at least one groove previously provided on at least one surface of the fertile iron sintered board as a starting point, or the fertile iron sintered board is divided into small pieces without forming a groove. Any of the above methods can be used.

Fat iron sintered plates are divided into triangles, quadrilaterals, polygons or combinations of any size by grooves. For example, the length of one side of a triangle, quadrilateral, or polygon is usually 1 to 12 mm. If the bonding surface of the object to be attached is a curved surface, it is preferably 1 mm or more and 1/3 or less of the radius of curvature, and preferably 1 mm. Above and below 1/4. When the groove is formed, the groove is not broken into an irregular shape at places other than the groove. Of course, the flat surface can also be closely adhered or substantially adhered to the cylindrical side curved surface and the surface with more or less unevenness.

The width of the opening of the groove formed in the fertilized iron sintered plate is usually preferably 250 μm or less, and more preferably 1 to 150 μm. If the width of the opening exceeds 250 μm, the magnetic permeability of the fat-grained iron sintered plate will decrease significantly, which is undesirable. In addition, the depth of the groove is usually 1/20~3/5 of the thickness of the fertile iron sintered plate. Still, if the thickness of the sintered fertilized iron plate is thinner than 0.1mm~0.2mm, the depth of the groove is preferably 1/20~1/4 of the thickness of the sintered fertilized iron plate, and preferably 1/ 20~1/6. [Example]

The following are examples of the present invention to illustrate the present invention in detail.

[Measurement of the specific surface area of the Fe ₂ O ₃ raw material] The specific surface area of the Fe ₂ O ₃ raw material was measured according to the BET method using "Macsorb HM model-1208" (manufactured by Mountech Co., Ltd.). The specific surface area of each Fe ₂ O ₃ raw material used in the Examples and Comparative Examples is described in Table 1.

[Determination of iron composition of fat grains] The composition of the pre-sintered fertilized iron powder for fertilized iron cores was measured using a multi-element simultaneous fluorescence X-ray analyzer Simultix 14 (Rigaku Co., Ltd.).

[Identification and quantification of crystalline phases] The crystallographic phase systems that make up fertilized iron are evaluated using D8 ADVANCE.

[Grain size, distortion, lattice constant] The grain size, distortion and lattice constant of fat-grained iron were evaluated in the same manner as the aforementioned X-ray diffraction, using D8 ADVANCE and TOPAS software Ver.4.

[Measurement of the magnetic properties of the fat iron core] 15 g of the above-mentioned fat iron pre-sintered powder for the fat iron core and 1.5 mL of the PVA aqueous solution diluted to 6.5% were put into a mold with an outer diameter of 20 mmφ and an inner diameter of 10 mmφ. , compressed by a press at 1 ton/ ^cm2 , and fired at 860, 880, 900, and 920°C for 2 hours to obtain the ring core of fat iron used to measure the initial magnetic permeability.

The initial magnetic permeability of the ring core was measured using an impedance/material analyzer E4991A (manufactured by Agilent Technologies Co., Ltd.) at frequencies of 100 kHz and 1 MHz.

[Measurement of sintered density of fat grain iron core] The sintered density of the fertilized iron sintered body for measuring the magnetic properties mentioned above was determined by measuring the outer diameter, inner diameter and weight, and then calculating.

Example 1: After weighing and wet-mixing each oxide raw material so that the composition of Ni-Zn-Cu fertilized iron becomes a specified composition, the mixed slurry was filtered and dried to obtain a raw material mixed powder. (As the Fe ₂ O ₃ raw material, the iron oxide (1) in Table 1 was used). The raw material mixed powder is fired in the air at 750 to 850° C. for 2 hours, and the obtained pre-fired product is pulverized using a vibrating mill to obtain Ni-Zn-Cu fertilized iron powder related to the present invention. The composition, crystal grain size, distortion, and lattice constant of the obtained powder are listed in Table 2.

The obtained Ni-Zn-Cu fertilized iron powder is made into a shaped body by the aforementioned method. This molded body was sintered in the air at a sintering temperature of 860 to 920° C. for 2 hours. The sintered density and initial magnetic permeability (100 kHz, 1 MHz) of the obtained fat-grained iron sintered body are shown in Table 2.

The obtained Ni-Zn-Cu fertilized iron was evaluated by XRD and was confirmed to be a single phase of spinel fertilized iron.

Examples 2 and 3: Except for making various changes to the composition range, the Ni-Zn-Cu fertilized iron powder was obtained in the same manner as in Example 1. The composition, crystal grain size and distortion of the obtained Ni-Zn-Cu fertilized iron powder are shown in Table 2. In addition, the obtained Ni-Zn-Cu fertilized iron powder was used to produce a fertilized iron sintered body in the same manner as in Example 1. The sintering density and initial magnetic permeability (100 kHz, 1MHz) are listed in Table 2.

Examples 4 and 5: Ni-Zn-Cu-Co fertilized iron powder was obtained in the same manner as in Example 1 except that the composition range was variously changed and Co was added. The composition, crystal grain size and distortion of the obtained Ni-Zn-Cu-Co fertilized iron powder are shown in Table 2. In addition, the Ni-Zn-Cu-Co fertilized iron powder obtained was used to prepare a fertile iron sintered body in the same manner as in Example 1. The sintering density and initial magnetic permeability of the fertile ferrous iron sintered body were ( 100kHz, 1MHz) are listed in Table 2.

Comparative example 1: Except for making various changes to the composition range, the Ni-Zn-Cu fertilized iron powder was obtained in the same manner as in Example 1. The composition, crystal grain size and distortion of the obtained Ni-Zn-Cu fertilized iron powder are shown in Table 2. In addition, the obtained Ni-Zn-Cu fertilized iron powder was used to produce a fertilized iron sintered body in the same manner as in Example 1. The sintering density and initial magnetic permeability (100 kHz, 1MHz) are listed in Table 2.

Comparative Example 2: Except that the iron oxide raw material (2) in Table 1 was used as the Fe ₂ O ₃ raw material, the Ni-Zn-Cu fertilized iron powder was obtained in the same manner as in Example 1. The composition, crystal grain size and distortion of the obtained Ni-Zn-Cu fertilized iron powder are shown in Table 2. In addition, the obtained Ni-Zn-Cu fertilized iron powder was used to produce a fertilized iron sintered body in the same manner as in Example 1. The sintering density and initial magnetic permeability (100 kHz, 1MHz) are listed in Table 2.

Comparative Example 3: Except that the iron oxide raw material (3) in Table 1 was used as the Fe ₂ O ₃ raw material, the Ni-Zn-Cu fertilized iron powder was obtained in the same manner as in Example 1. The composition, crystal grain size and distortion of the obtained Ni-Zn-Cu fertilized iron powder are shown in Table 2. In addition, the obtained Ni-Zn-Cu fertilized iron powder was used to produce a fertilized iron sintered body in the same manner as in Example 1. The sintering density and initial magnetic permeability (100 kHz, 1MHz) are listed in Table 2.

Comparative Example 4: Ni-Zn-Cu fertilized iron powder was obtained in the same manner as in Example 1, except that the iron oxide raw material (4) in Table 1 was used as the Fe ₂ O ₃ raw material. The composition, crystal grain size and distortion of the obtained Ni-Zn-Cu fertilized iron powder are shown in Table 2. In addition, the obtained Ni-Zn-Cu fertilized iron powder was used to produce a fertilized iron sintered body in the same manner as in Example 1. The sintering density and initial magnetic permeability (100 kHz, 1MHz) are listed in Table 2.

Comparative Example 5: Ni-Zn-Cu-Co granular iron powder was obtained in the same manner as in Example 4, except that the iron oxide raw material (2) in Table 1 was used as the Fe ₂ O ₃ raw material. The composition, crystal grain size and distortion of the obtained Ni-Zn-Cu-Co fertilized iron powder are shown in Table 2. In addition, the Ni-Zn-Cu-Co fertilized iron powder obtained was used to prepare a fertile iron sintered body in the same manner as in Example 1. The sintering density and initial magnetic permeability of the fertile ferrous iron sintered body were ( 100kHz, 1MHz) are listed in Table 2.

Comparative Example 6: Except that the iron oxide raw material (2) in Table 1 was used as the Fe ₂ O ₃ raw material, the Ni-Zn-Cu-Co fertilized iron powder was obtained in the same manner as in Example 5. The composition, crystal grain size and distortion of the obtained Ni-Zn-Cu-Co fertilized iron powder are shown in Table 2. In addition, the Ni-Zn-Cu-Co fertilized iron powder obtained was used to prepare a fertile iron sintered body in the same manner as in Example 1. The sintering density and initial magnetic permeability of the fertile ferrous iron sintered body were ( 100kHz, 1MHz) are listed in Table 2.

The Ni-Zn-Cu-based fertilized iron powder related to the present invention has a sintering density of 5.00 g/cm ³ or more even when it is sintered at a low temperature such as 860°C, and the conductivity at 100 kHz and 1 MHz is When compared at the same sintering temperature, the magnetic coefficient is higher than that of the comparative example. Therefore, it is suitable as a precursor for ferrous iron sintered bodies and fertile iron flakes, and as magnetic powder for laminated chip inductors, inductance components, and other electronic components.

Claims (5)

A Ni-Zn-Cu series fertilized iron powder, characterized by containing less than 49 mol% Fe ₂ O ₃ , 5 to 25 mol% NiO, 15 to 40 mol% ZnO, 5 to 15 mol% CuO and 0 to 3 mol% CoO, the crystal grain size is 180 nm or less, wherein the aforementioned Ni-Zn-Cu-based iron powder is composed of a spinel iron single phase. For example, the Ni-Zn-Cu series fertilized iron powder of claim 1 has a value of 0.330 or less excluding distortion. For example, the Ni-Zn-Cu based fertilized iron powder of Claim 1 has a sintering density of 5.00g/cm3 ^or more when fired at 860°C in the air. A sintered body using the Ni-Zn-Cu series fertilized iron powder according to any one of claims 1 to 3. A kind of fat iron flakes, which is the Ni-Zn-Cu series fat iron powder according to any one of the application requirements 1 to 3.