METHOD OF PRODUCING HIGH-COERCIVITY MATERIALS BASED ON STRONTIUM HEXAFERRITE Russian patent published in 2009 - IPC H01F1/03 H01F1/11 C04B35/26 C01G49/00 

FIELD: chemistry.

SUBSTANCE: invention relates to the technology of producing hard magnetic materials, which can be used for making magnetic powders, permanent magnets, resin-bonded magnets, magnetic liquids for different purposes, as well as high-density magnetic recording devices. The method of obtaining particles of strontium hexaferrite, doped with aluminium, involves preparation of a molten composition of SrFe₁₂-_yAl_yO₁₉+n·(SrAl₂O₄+Sr₂B₂O₅), where 0.5≤y≤2.0, 3≤n≤5, hardening the melt and thermal treatment of the material formed from hardening at temperature ranging from 850 to 1000°C for not less than 1 hour. As a result, glass-ceramic material is formed, which contains particles of strontium hexaferrite with composition SrFe₁₂-_xAl_xO₁₉, where x=0.5 to 2, and diametre of 200 to 500 nm. The method also allows for extracting particles of strontium hexaferrite when obtained materials are dissolved in solutions of hydrochloric and acetic acid.

EFFECT: invention allows for obtaining materials based on strontium hexaferrite with high coercitive force (not less than 8000 Oe) and saturation magnetisation of not less than 40 emu/g.

3 cl, 2 ex, 4 dwg