Mn-zn ferrite containing less than 50 mol% fe2o3

A ferrite, V2O5 technology, applied in the direction of magnetic objects, magnetic materials, inorganic materials, etc., can solve the problem that resistance is not very effective, it is difficult to Mn-Zn ferrite at the same time, and it can meet the needs of soft magnetism and resistance.

Inactive Publication Date: 2004-08-18
MINEBEA CO LTD
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  • Description
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Problems solved by technology

If such a large amount of Mn is included 3+ , it is difficult to make Mn-Zn ferrite meet the needs of soft magnetism and resistance
[0010] On the other hand, the Mn-Zn ferrite disclosed in the above-mentioned Japanese Patent No. 3108803 contains small amounts of CaO and SiO 2 , specifically, 0.005-0.20% by mass of CaO and 0.005-0.05% by mass of SiO 2 , so it is not very effective in increasing the resistance
If CaO and SiO are added to increase resistance 2 If the content is high, abnormal grain growth will occur during sintering, and the magnetic properties (soft magnetic properties) will be significantly damaged

Method used

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  • Mn-zn ferrite containing less than 50 mol% fe2o3

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Experimental program
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Embodiment

[0027] Eleven different test samples, including 4 comparative samples, were made with the composition shown in Table 1. Raw material powder Fe 2 o 3 , ZnO and MnO were mixed, stirred with an attritor, calcined at 850° C. in air for 2 hours, and ground with an attritor for 1 hour to obtain a mixture powder. Then, the TiO 2 , SnO 2 , CaO, SiO 2 , CuO, Nb 2 o 5 and V 2 o 5 The powder is properly added to the mixture powder to adjust the components, then the adjusted mixture powder is stirred for 1 hour with a grinder, added polyvinyl alcohol to granulate, and pressed into a ring core (green body) under a pressure of 80MPa, each The outer diameter is 25mm, the inner diameter is 15mm, and the height is 5mm. The green body was sintered at 1200° C. for 2 hours and then cooled in the furnace. The atmosphere therein was controlled by filling nitrogen into the furnace to obtain the oxygen partial pressure at which the constant b in formula (1) was set at 9 o’clock. Inventive s...

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Abstract

An Mn-Zn ferrite includes base components of 44.0 to 49.8 mol % Fe 2 O 3 , 4.0 to 26.5 mol % ZnO, at least one of 0.1 to 4.0 mol % TiO 2 and SnO 2 , 0.5 mol % or less Mn 2 O 3 , and the remainder consisting of MnO, and contains 0.20 (0.20 excluded) to 1.00 mass % CaO as additive. Since the Mn-Zn ferrite contains less than 50 mol % Fe 2 O 3 and a limited amount (0.5 mol % or less) of Mn 2 O 3 , an abnormal grain growth does not occur even if CaO content is more than 0.20 mass %, and a high electrical resistance can be gained. And, since an appropriate amount of TiO 2 and / or SnO 2 is contained, an initial permeability is kept adequately high, whereby an excellent soft magnetism can be achieved in a high frequency band such as 1 MHz.

Description

technical field [0001] The present invention relates to a typical soft magnetic oxide magnetic material, and more particularly, to a low-loss material suitable for use in switching power supplies, various inductive elements, impedance elements in EMI countermeasures, electromagnetic wave absorbers, etc. Mn-Zn ferrite. Background technique [0002] Mn-Zn ferrite is one of the typical soft magnetic oxide magnetic materials, and the basic components usually include: Fe 2 o 3 More than 50.0 mol% of stoichiometry, the average is 52.0-55.0 mol%; ZnO is 10.0-24.0 mol%; the rest is composed of MnO, usually manufactured in this way, Fe is weighed according to the predetermined mixing ratio 2 o 3 , ZnO and MnO raw material powders, which are mixed, calcined, ground, adjusted components, granulated, and then pressed into a green body with a predetermined shape, and the green body is sintered at a temperature of 1200-1400 ° C in a reducing atmosphere 2 -4 hours, the oxygen partial p...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F1/00C04B35/26H01F1/34
CPCC04B2235/3418C04B2235/3239C04B2235/3281H01F1/344C04B2235/3284C04B2235/3293C04B35/63C04B2235/3232C04B35/2658C04B2235/3208C04B2235/3251C04B2235/604C04B2235/96C04B2235/6584C04B2235/83C04B2235/3262C04B2235/94C04B2235/3256C04B2235/3244
Inventor 小林修山田修伊藤清
Owner MINEBEA CO LTD
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