Heat Treating Barium Ferrite Particles to Improve Their Magnetic Properties
Original Publication Date: 1984-Nov-01
Included in the Prior Art Database: 2005-Feb-05
Barium ferrite (Ba0.6Fe203) has a highly anisotropic hexagonal crystal structure which exhibits high magnetocrystalline anisotropy. Platelet-like barium ferrite crystals have a direction of easy magnetization and hexagonal c axis perpendicular to the plane of the platelet. The "c" axis referred to here is the crystallographic "z" axis. These features make them suitable for use in vertical recording media. Unfortunately, the barium ferrite crystal has a very high coercivity which, if not reduced, would render the crystal unsuitable for vertical recording. The coercivity has been reduced by substituting CoII-TiIV ion pairs for two of the FeIII ions in the barium ferrite crystal.