JPH08151258A - Oxide magnetic material - Google Patents

Abstract

PURPOSE: To obtain an oxide magnetic material having high magnetic permeability and making usable of Ag, Ag-Pd or Ag-Cu, etc., as an inner conductor. CONSTITUTION: This magnetic material contains Fe in an amount of 45.0-50.0mol% reducing to Fe2 O3 , Ni in an amount of 15.0-30.0mol% reducing to NiO, Cu in an amount of 8.0-15.0mol% reducing to CuO, Zn in an amount of 15.0-25.0mol% reducing to ZnO, at least a metal selected from Mg, Ca, Sr, Ba, Mo, W, V and Cr in the total of 0.1-3.0mol% respectively reducing to MgO, CaO, SrO, BaO, MoO, WO, V2 O5 , and Cr2 O3 , and Li in an amount of 0.01-3.0mol% reducing to Li2 O.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oxide magnetic material used for electric parts such as inductors.

[0002]

2. Description of the Related Art Ni-Cu-Zn type ferrite oxide magnetic material is known as an oxide magnetic material used for electric parts such as inductors. For example, JP-A-50-10
No. 7008 discloses a Ni—Cu—Zn-based high resistivity, low loss oxide magnetic material.

[0003]

However, when the conventional Ni-Cu-Zn-based oxide magnetic material is used, it is difficult to obtain a satisfactory magnetic permeability when the shape of the chip or the like becomes small. Moreover, since the firing temperature is relatively high at 1000 ° C. or higher, Ag, Ag—Pd, Ag—
It was impossible to use a metal conductor such as Cu having a melting point lower than 1000 ° C. Therefore, an object of the present invention is to provide an oxide magnetic material having a high magnetic permeability, which enables use of a metal conductor such as Ag, Ag-Pd, or Ag-Cu as an inner conductor. .

[0004]

In order to achieve the above-mentioned object, the oxide magnetic material of the present invention has Fe converted to Fe ₂ O ₃ of 45.0 to 50.0 mol% and Ni converted to NiO. 15.0 to 30.0 mol%, Cu to CuO is 8.0 to 15.0 mol%, and Zn is to ZnO to be 1
5.0-25.0 mol%, Mg, Ca, Sr, Ba,
At least one metal selected from Mo, W, V and Cr is MgO, CaO, SrO, BaO and Mo, respectively.
O, 0.1 to a total in terms WO, the _{V 2 O 5, Cr 2 O} 3
3.0 mol% and 0.01 in terms of Li converted to Li ₂ O
It is characterized by containing ~ 3.0 mol%. Such oxide magnetic materials can be fired at temperatures below 950 ° C. Also,
In the above oxide magnetic material, Mg, Ca, Sr, B
Instead of at least one metal selected from a, Mo, W, V and Cr, Mg, Ca, Sr, Ba, Mo,
At least one metal selected from W, V and Cr and M
n and MgO, CaO, SrO, BaO, Mo respectively
_{O, WO, V 2 O 5} , Cr 2 O 3, Mn preferably be contained 0.1～3.0Mol% in total in terms of the ₃ O _4.
This oxide magnetic material can also be fired at temperatures below 950 ° C.

[0005]

According to the oxide magnetic material of the present invention, the magnetic permeability can be improved without lowering the specific resistance.
That is, the specific resistance is 1000 MΩ · cm or more and the magnetic permeability is 250.
An oxide magnetic material having the above is obtained. Also, 950
Baking at below ℃ becomes possible, and Ag, Ag-
Pd, Ag-Cu, etc. can be used.

[0006]

EXAMPLES The present invention will be described in detail below based on examples and comparative examples. Fe ₂ O ₃ , NiO, CuO, ZnO,
MgO, CaO, SrO, BaO, MoO, WO, V ₂
O ₅ , Cr ₂ O ₃ and / or Mn ₃ O _{4 and} LiC corresponding to 0.01 to 3.0 mol% of Li ₂ O after baking
1 was weighed in the proportions shown in Tables 1 to 3, wet-mixed, dehydrated and dried. Approximately 700-
It was calcined at a temperature in the range of about 800 ° C. for 1 hour and then crushed by a ball mill for 15 hours. An organic binder was added to this, and the mixture was granulated, molded, and fired in the atmosphere at a temperature in the range of about 850 to about 950 ° C for 1 hour. The magnetic permeability μ and the specific resistance ρ of the sintered body thus obtained were measured. The magnetic permeability was measured at a frequency of 100 MHz and a voltage of 0.5 V, and the specific resistance was measured at a voltage of 25 V and a holding time of 20 seconds. The obtained results are shown in Tables 1-3. In addition, sample No. 1 in Tables 1-3.
Those marked with * are outside the composition range of the present invention and are comparative examples.

[0007]

[Table 1]

[0008]

[Table 2]

[0009]

[Table 3]

As is clear from Tables 1 to 3, the oxide magnetic materials within the composition range specified in the present invention have a magnetic permeability μ of 2 or less.
It has a characteristic of 50 or more and a specific resistance ρ of 1000 MΩ · cm or more. Also, firing at 950 ° C. or lower is possible. On the other hand, an oxide magnetic material having a composition range outside the range of the present invention cannot obtain the above-mentioned desired characteristics.

The reason for limiting the composition range of each component will be described based on the results shown in Tables 1 to 3. Regarding Fe ₂ O _{3, if} it is less than 45.0 mol%, both the magnetic permeability and the specific resistance are low (Sample No. 1), and if it exceeds 50.0 mol%, it is 9
It does not sinter at 00 ° C (Sample No. 5). Regarding NiO, if it is less than 15.0 mol%, the specific resistance is low (Sample N
o. 6) If it exceeds 30.0 mol%, the magnetic permeability is low (Sample No. 9). For CuO, 8.0 mol%
If it is less than 900 ° C, it does not sinter at 900 ° C (Sample No. 10), 1
When it exceeds 5.0 mol%, both the magnetic permeability and the specific resistance are low (Sample No. 11). For ZnO, 15.0mo
If it is less than 1%, both the magnetic permeability and the specific resistance are low (Sample No.
12) If it exceeds 25.0 mol%, the specific resistance is low (Sample No. 15). MgO, CaO, SrO, BaO, M
Regarding oO, WO, V ₂ O ₅ and Cr ₂ O ₃ , if the sum of them is less than 0.1 mol%, the magnetic permeability is low (Sample No.
16), if it exceeds 3.0 mol%, the specific resistance is low or it does not sinter at 900 ° C. (Sample No. 19, 49 to 5).
5). Regarding Li ₂ O, if it is less than 0.01 mol%, it does not sinter at 900 ° C. (Sample No. 20), and 3.0 mo
If it exceeds 1%, the specific resistance is low (Sample No. 23).

Further, MgO, CaO, SrO, BaO,
If the sum of MoO, WO, V ₂ O ₅ , Cr ₂ O ₃ and Mn ₃ O ₄ is less than 0.1 mol%, the magnetic permeability is low (Sample No. 1).
6), if it exceeds 3.0 mol%, it does not sinter at 900 ° C. (Sample Nos. 56 and 57). Although Li oxide was used as LiCl at the time of compounding in the above-mentioned Examples and Comparative Examples, it is not limited to this and, for example, Li
₂ O, Li ₂ CO ₃ , Li organic acid salts and the like can also be used. Further, in the case of other metals, for example, its oxide or carbonate can be used as a raw material.

[0013]

As described above in detail, according to the present invention, an oxide having a specific resistance of 1000 MΩ · cm or more and a magnetic permeability of 250 or more can be obtained by appropriately selecting the composition ratio of the constituent components of the oxide magnetic material. A magnetic material is obtained. 950
Since it can be fired at a temperature below ℃,
It enables the use of low melting point metal conductors such as g, which is extremely useful in industry.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display H01F 1/34

Claims (4)

[Claims] 1. Fe is converted to Fe ₂ O ₃ and it is 45.0-5.
0.0 mol%, Ni converted to NiO, 15.0 to 3
0.0 mol%, Cu converted to CuO 8.0-1
5.0 mol%, Zn converted to ZnO, 15.0 to 2
5.0 mol%, Mg, Ca, Sr, Ba, Mo, W,
MgO, CaO, SrO, BaO, MoO, WO, and V each containing at least one metal selected from V and Cr.
Converted to ₂ O ₅ and Cr ₂ O ₃ , 0.1 to 3.0 mol in total
% And Li converted to Li ₂ O, 0.01 to 3.0 m
An oxide magnetic material characterized by containing ol%. 2. The oxide magnetic material according to claim 1, which is fired at a temperature of 950 ° C. or lower. 3. Fe is converted to Fe ₂ O ₃ and 45.0 to 5
0.0 mol%, Ni converted to NiO, 15.0 to 3
0.0 mol%, Cu converted to CuO 8.0-1
5.0 mol%, Zn converted to ZnO, 15.0 to 2
5.0 mol%, Mg, Ca, Sr, Ba, Mo, W,
At least one metal selected from V and Cr and Mn are MgO, CaO, SrO, BaO, MoO, and
_{WO, V 2 O 5, Cr} 2 O 3, Mn 3 O 4 include 0.01～3.0Mol% of 0.1～3.0Mol% and Li in total in terms in terms of Li ₂ O to An oxide magnetic material characterized by. 4. The oxide magnetic material according to claim 3, which is fired at a temperature of 950 ° C. or lower.