Preparation method of rare earth-doped nanometer strontium ferrite permanent magnet material

Abstract

The invention discloses a preparation method of a rare earth-doped nanometer strontium ferrite permanent magnet material. The chemical composition formula of rare earth-doped strontium ferrite is Sr<1-x>Ln<x>Fe<12-x>A<x>O<19>, wherein the element Ln in the formula is a rare earth element such as La and Yb, the element A is a divalent transition metal element such as Co, and x is greater than or equal to 0 and less than or equal to 0.2. According to the preparation method, a Sr<1-x>Ln<x>Fe<12-x>A<x>O<19> precursor is continuously prepared through a Taylor reactor, and then grinding and high-temperature sintering are carried out to obtain the rare earth-doped strontium ferrite; the precursor with good crystallinity and a size of 100-200 nm can be obtained through the preparation method; thestrontium ferrite obtained after co-doping and sintering of the rare earth element and the metal element is higher in magnetic performance and better in performance; and the preparation method can effectively reduce high-temperature sintering temperature and time, saves energy consumption, and is suitable for industrial production.

Description

technical field [0001] The invention relates to a preparation method of a rare earth-doped nanometer strontium ferrite permanent magnet material, which belongs to the field of magnetic materials. Background technique [0002] In recent years, ferrite materials have been developed rapidly. Among them, rare earth strontium ferrite materials are favored by virtue of their advantages such as uniaxial magnetic dissimilarity, high coercive force, high Curie temperature, strong chemical stability, and superior cost performance. received widespread attention. [0003] However, ferrite materials prepared by traditional high-temperature solid-state sintering have complicated process flow, long sintering time, and high temperature requirements, resulting in very high energy consumption, and the prepared ferrite materials have low uniformity. [0004] In order to improve the magnetic properties of ferrite materials and reduce energy consumption, researchers used sol-gel method and co-p...

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Problems solved by technology

[0003] However, the ferrite material prepared by traditional high-temperature solid-state sintering has complex process flow, long sintering time, and high temperature requirements, resulting in very high energy consumption and low uniformity of the prepared ferrite material

[0004] In order to improve the magnetic properties of ferrite materials and reduce energy consumption, researchers used sol-gel method and co-precipitation method to prepare nano-scale to micro-scale ferrite materials, which improved the magnetic properties of materials, such as patent CN201210418388.8, CN201110102232.4, CN106082349A, CN201310601472.8, CN108554414A and CN108046791A and other nano-ferrite preparation methods, but the amount of ferrite prepared by this co-precipitation method is generally small, the repeatability is poor, and it cannot be produced continuously. The pollution caused by the glue method is relatively large, and the shape is uncontrollable, so neither of these two methods can be used in actual industrial production on a large scale.

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