Method for synthesizing soft-hard exchange coupling magnet by chemical coprecipitation molten salt method

A technology of chemical co-precipitation and exchange coupling, which is used in the field of chemical co-precipitation molten salt method to synthesize soft-hard exchange coupling magnets. The problem of phase composition deviation, etc., to achieve the effect of simple and easy process and promoting low-temperature synthesis of phase

Active Publication Date: 2019-08-30
南京睿磐内尔环保复合新材料有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The problem is that the loss of materials and the introduction of impurities during the ball milling process often lead to the deviation of the two-phase composition of the final product. In addition, the heat treatment synthesis process is limited by the uniformity of the mixture, and it is difficult to obtain a composite magnet with a good exchange coupling effect.

Method used

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  • Method for synthesizing soft-hard exchange coupling magnet by chemical coprecipitation molten salt method
  • Method for synthesizing soft-hard exchange coupling magnet by chemical coprecipitation molten salt method
  • Method for synthesizing soft-hard exchange coupling magnet by chemical coprecipitation molten salt method

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Embodiment 1

[0037] Soft-hard exchange coupled magnet xCoFe 2 o 4 CoFe in / yBaM 2 o 4 Synthesis with BaM component ratio x:y=2:1: According to the stoichiometric ratio, weigh barium nitrate, ferric nitrate nonahydrate, and cobalt nitrate hexahydrate, dissolve them in deionized water, stir and dissolve until clear and transparent, and obtain mixed metal salts Solution, wherein the iron ion concentration is 0.5mol / L; With sodium hydroxide and sodium carbonate as precipitant, add deionized water, prepare precipitant solution wherein the concentration of sodium hydroxide is 5.0mol / L, and the concentration of sodium carbonate is 0.1mol / L; and under the condition of rapid stirring, the initial metal ion solution obtained in 1) is added to the precipitant solution, and the flow rate is controlled at 200~500ml / min; after stirring and reacting for 2~6 hours, separate by suction filtration, and use Wash with deionized water until the filtrate is neutral to obtain a filter cake; the obtained filt...

Embodiment 2

[0040] Soft-hard exchange coupled magnet xCoFe 2 o 4 CoFe in / yBaM 2 o 4 Synthesis with BaM component ratio x:y=1:2: According to the stoichiometric ratio, weigh barium nitrate, ferric nitrate nonahydrate, and cobalt nitrate hexahydrate and dissolve them in deionized water, stir and dissolve until clear and transparent, and obtain mixed metal salts Solution, wherein the iron ion concentration is 0.5mol / L; With sodium hydroxide and sodium carbonate as precipitant, add deionized water, prepare precipitant solution wherein the concentration of sodium hydroxide is 5.0mol / L, and the concentration of sodium carbonate is 0.2mol / L; and under the condition of rapid stirring, the initial metal ion solution obtained in 1) is added to the precipitant solution, and the flow rate is controlled at 200~500ml / min; after stirring and reacting for 2~6 hours, separate by suction filtration, and use Wash with deionized water until the filtrate is neutral to obtain a filter cake; the obtained f...

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Abstract

The invention relates to the technical field of functional materials, in particular to a method for synthesizing a soft-hard exchange coupling magnet by a chemical coprecipitation molten salt method.The method comprises the following steps: weighing raw materials according to a stoichiometric ratio of CoFe2O4 and BaM components in xCoFe2O4 / yBaM, preparing a mixed metal salt solution, preparing aprecipitating agent, adding the mixed metal salt solution into the precipitating agent, performing stirring and carrying out a reaction for a period of time, performing vacuum filtration and separation to obtain a filter cake, performing oven drying on the filter cake to constant weight, performing crushing and grinding to obtain a precursor powder, mixing the precursor powder with a salt, performing ball milling to obtain a mixed product, performing heat treatment on the mixed product, washing the product, performing filtering, and performing oven drying on the product after filtration to obtain a ferrite powder. According to the method, chemical coprecipitation metal ion uniform mixing and molten salt heat treatment crystal growth control are combined, and the precision synthesis of thesoft-hard exchange coupling magnet two-component composite ferrite and the control of a particle structure are realized through component adjustment, composite precipitant optimization, molten salt heat treatment instead of traditional heat treatment, and other technical means.

Description

technical field [0001] The invention relates to the technical field of functional materials, and relates to the preparation of composite magnetic oxides, in particular to a method for synthesizing soft-hard exchange coupling magnets by chemical co-precipitation molten salt method. Background technique [0002] M-type hexagonal barium ferrite (BaM) with hard magnetic properties has good microwave absorption properties, and is often used as an electromagnetic wave absorption magnetic loss medium. The absorption band is high and the bandwidth is narrow. Compared with BaM hard ferrite, spinel type soft ferrite is limited to lower frequency due to its lower anisotropy field. Therefore, spinel-type soft ferrite can be combined with BaM hard ferrite to reduce the magnetocrystalline anisotropy of BaM, and the exchange coupling effect of soft-hard ferrite can be adjusted by adjusting the ratio of the two-phase components in the composite system. And the polarization of the two-phas...

Claims

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Application Information

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IPC IPC(8): C01G51/00
CPCC01G51/00C01G49/0036C01P2004/80C01P2002/72C01P2004/03C01P2004/61
Inventor 刘俊亮杨敏江辉史斌
Owner 南京睿磐内尔环保复合新材料有限公司
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