JP2001167921A - High permeability oxide magnetic material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain fluctuations of initial permeability due to temperature changes to be small, in a high permeability oxide magnetic material which is used for magnetic components such as noise filter, choke coil and pulse transformer. SOLUTION: TiO2 in a range of 0.1-2% and CO3O4 in a range of 0.01-0.2% are added to main component of Mn-Zn ferrite, and a secondary peak of initial permeability is made to appear in a range of -40 to 0 deg.C. Thereby not only the crystal magnetic anisotropy but also initial permeability of Mn-Zn ferrite are changed by compound addition of two kinds of subcomponents TiO2 and CO3O4, but also the temperature characteristic of Mn-Zn ferrite is changed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high-permeability oxide magnetic material made of Mn-Zn ferrite and used for magnetic components such as a noise filter, a choke coil, and a pulse transformer.

[0002]

This kind of high-permeability oxide magnetic material has an attribute that the initial permeability of Mn-Zn ferrite depends on temperature. If it changes, the magnetic characteristics inevitably change. Therefore, in order to expand the applications of the high-permeability oxide magnetic material, it is necessary to devise such that the initial permeability does not increase or decrease as much as possible over a wide temperature range.

[0003] In view of such circumstances, an object of the present invention is to provide a high-permeability oxide magnetic material capable of suppressing a change in initial permeability due to a temperature change.

[0004]

That is, the high-permeability oxide magnetic material according to the present invention comprises 50 to 58 mol of Fe ₂ O ₃ .
%, MnO 12 to 47 mol%, and ZnO 3 to 30 mol% in a high permeability oxide magnetic material composed of Mn-Zn ferrite in a range of 0.1 to 2% based on the main component of Mn-Zn ferrite. was added Co ₃ O ₄ in the range of TiO ₂ and 0.01 to 0.2 percent of the inner as an auxiliary component, the secondary peak of the initial permeability is configured as a -40~0 ℃. By adopting such a configuration, the crystal magnetic anisotropy thus initial permeability Mn-Zn ferrite is changed by the combined addition of two sub-components TiO _2, Co ₃ O _4, the temperature characteristic of the for Mn-Zn ferrite Acts to change.

The composition ratio of the main component of the Mn-Zn ferrite is limited so that the Curie temperature is 160 ° C. or higher. With this configuration, the temperature difference between the temperature at which the secondary peak of the initial permeability and the Curie temperature are equal to or more than a predetermined value is ensured, and the change in the initial permeability during that time is moderate.

Further, the main component of the above Mn-Zn ferrite is
0.01 to 2% MoO per minute _ThreeAnd 0.1% or less
CaCO below_ThreeIs added as an auxiliary component. Or
With this configuration, the frequency characteristic of the initial magnetic permeability is
O_ThreeAt the same time as the addition of MoO
_ThreeAddition promotes grain growth of Mn-Zn ferrite
And acts to increase the initial magnetic permeability.

[0007] Throughout the present specification, "mol%" used as a unit of the composition ratio of the main component represents a mole percentage (percentage when compared with the number of moles). “%” Used as a unit indicates mass percentage.

[0008]

Embodiments of the present invention will be described below.

52.8 mol% of Fe ₂ O ₃ , MnO 30.
Mn- containing 3 mol% and 16.9 mol% of ZnO as main components
Four types of subcomponents TiO ₂ , C
o ₃ O ₄ , MoO ₃ , and CaCO ₃ were added in different amounts, and 10 kinds of high-permeability oxide magnetic materials (No.
1 to 10) were produced. As shown in Table 1, these high-permeability oxide magnetic materials have the same Curie temperature as the composition ratio of the main components of Mn—Zn ferrite (Table 1).
(Tc) is 175 ° C., so that a difference between the temperature at which the secondary peak of the initial permeability and the Curie temperature are equal to or more than a certain value is secured, and the initial permeability gradually changes during that time. Will be.

[0010]

[Table 1]

With respect to these ten kinds of high-permeability oxide magnetic materials, the initial magnetic permeability at each temperature was determined by appropriately changing the temperature within the range of -40 to 130 ° C. Further, based on the initial magnetic permeability thus determined, a relative temperature coefficient of the initial magnetic permeability is calculated using a definition equation (according to JIS C2560) shown in Equation 1 in order to evaluate the degree of change of the initial magnetic permeability due to a temperature change. The results shown in Table 2 were obtained.

[0012]

[Number 1] _{α μir = (μ 2 -μ 1} ) / {μ 1 2 (T 2 -T 1)} α μir: relative temperature coefficient of initial permeability mu _1: initial permeability at a reference temperature T ₁ mu ₂ : Initial permeability at temperature T ₂

[0013]

[Table 2]

From the above, the following conclusions are drawn.

First, if the auxiliary component Co ₃ O ₄ is added,
As is clear from FIG. 1, the fluctuation of the initial magnetic permeability is small, but when the addition amount exceeds 0.2%, the initial magnetic permeability is significantly reduced.

Second, if a sub-component TiO ₂ is added in addition to the sub-component Co ₃ O ₄ , the crystal magnetic anisotropy constant of the Mn—Zn ferrite changes, and a wide temperature range from a low temperature to a high temperature is obtained. Over time, the fluctuation range of the initial permeability decreases.
For example, as it is clear from Table 2, as the secondary peak of the initial permeability was selected amount of the main component Fe ₂ O ₃ subcomponents with respect to TiO _2, Co ₃ O ₄ is -40～0 ° C. By doing so, the relative temperature coefficient of the initial permeability at low temperature is-
From 1 to 1, the relative temperature coefficient of the initial permeability at high temperature is 0 to
2 can be suppressed. At this time, when the secondary peak of the initial magnetic permeability is lower than −40 ° C., as shown in FIG.
The initial magnetic permeability is significantly reduced in a temperature range from a temperature at which a secondary peak of the initial magnetic permeability occurs to the Curie temperature.

Third, if the auxiliary component MoO ₃ is added, M
Grain growth of n-Zn ferrite is promoted, and a high initial magnetic permeability is obtained. However, if the addition amount of the sub-component MoO ₃ exceeds 2%, abnormal grain growth occurs and the initial permeability decreases.

Fourth, if the auxiliary component CaCO ₃ is added,
As is clear from FIG. 3, the frequency characteristic of the initial permeability is improved, but as the amount of addition increases, the initial permeability decreases. Particularly, when the addition exceeds 0.1%, the decrease in the initial permeability is remarkable. Become.

[0019]

As described above, according to the present invention,
Fe ₂ O ₃ 50 to 58 mol%, MnO 12 to 47 mol
%, ZnO 3 to 30 mol% in a high permeability oxide magnetic material comprising Mn-Zn ferrite as a main component, and 0.1 to 2% with respect to the main component of the Mn-Zn ferrite.
The Co ₃ O ₄ in the range of TiO ₂ and from 0.01 to 0.2% of the range of added as an auxiliary component, the secondary peak of the initial permeability was constructed as a -40～0 ° C. So M
magnetocrystalline anisotropy and hence initial permeability n-Zn ferrite is changed by the combined addition of two sub-components TiO _2, Co ₃ O _4, since the temperature characteristics of the for Mn-Zn ferrite is changed, due to a temperature change It is possible to provide a high-permeability oxide magnetic material that can suppress the fluctuation of the initial permeability and can be used for a wide range of applications.

According to the present invention, the Curie temperature is 1
Since the composition ratio of the main component of the Mn-Zn ferrite is limited so as to be 60 ° C. or higher, the temperature difference between the temperature at which the secondary peak of the initial permeability and the Curie temperature are maintained at a certain value or more, Since the change in the initial magnetic permeability during this period becomes gradual, the above-mentioned effects become more remarkable.

Further, according to the present invention, the above Mn-Zn
MoO _{3 of} 0.01 to 2% based on the main component of ferrite
And 0.1% or less of CaCO ₃ added as a sub-component, the frequency characteristic of the initial magnetic permeability is
At the same time as the addition of O ₃ improves the content,
The addition of ₃ promotes the grain growth of Mn-Zn ferrite and increases the initial magnetic permeability, so that the above-mentioned effects become more remarkable.

[Brief description of the drawings]

FIG. 1 is a graph showing temperature characteristics of initial magnetic permeability of four types of high-permeability oxide magnetic materials having different addition amounts of an auxiliary component Co ₃ O ₄ .

FIG. 2 is a graph showing temperature characteristics of initial permeability of five kinds of high-permeability oxide magnetic materials having different secondary peaks in initial permeability.

FIG. 3 is a graph showing temperature characteristics of initial magnetic permeability of three kinds of high-permeability oxide magnetic materials having different addition amounts of a subcomponent CaCO ₃ .

Continued on the front page (72) Inventor Yoshio Matsuo 5-36-11 Shimbashi, Minato-ku, Tokyo Inside Fuji Electric Chemical Co., Ltd. (72) Inventor Shinji Fukunaga 5-36-11 Shimbashi, Minato-ku, Tokyo Fuji Electric Chemical Co., Ltd. In-house F-term (reference) 4G002 AA07 AE02 4G018 AA01 AA02 AA15 AA21 AA25 AA39 5E041 AB02 AB19 BD01 CA02 NN02 NN15

Claims (3)

[Claims] 1. 50 to 58 mol% of Fe ₂ O ₃ , MnO1
In a high-permeability oxide magnetic material composed of Mn-Zn ferrite containing 2 to 47 mol% and ZnO of 3 to 30 mol% as main components, the main component of Mn-Zn ferrite is 0.1 to 2 mol%.
% Of TiO ₂ and 0.01 to 0.2% of Co ₃ O ₄ are added as subcomponents so that the secondary peak of initial permeability becomes −40 to 0 ° C. A high-permeability oxide magnetic material characterized by the following. 2. The high-permeability oxide magnetic material according to claim 1, wherein the composition ratio of the main component of Mn—Zn ferrite is limited so that the Curie temperature is 160 ° C. or higher. 3. MoO ₃ of 0.01 to 2% and CaC of 0.1% or less based on the main component of Mn—Zn ferrite.
2. The method according to claim 1, wherein O ₃ is added as an auxiliary component.
Alternatively, the high-permeability oxide magnetic material according to claim 2.