Angular Variation of Coercive Force in Barium Ferrite

Magnetization reversals in high magnetocrystalline anisotropy materials like barium ferrite are believed to take place by coherent rotation or by reverse-domain nucleation. The former mechanism gives rise to a Stoner-Wohlfarth type of angular variation of coercive force and the latter mechanism gives rise to Kondorsky-type behavior. Angular variation of coercive force was measured in several oriented particle assemblies with the average particle size ranging from 0.4 to 200 μ. The results were interpreted by a simple model incorporating SW and Kondorsky behavior.