Composition dependence of the magnetic properties of banded magnets of strontium hexaferrite-polyvinyl chloride

A systematic study of the magnetic properties of strontium ferrite-polyvinyl chloride plastoferrites as a function of composition is presented. Plastoferrites were manufactured by hot compression of a mixture of commercial powders of strontium ferrite (SrFe12O19) and polyvinyl chloride. In order to explain the dependence of the volumetric density and the saturation magnetization with composition, an additive model for these properties is considered. The intrinsic coercivity shows a decrease with increasing strontium ferrite content, which is interpreted as a magnetizing-like effect due to the increasing interaction between the magnetic particles. The maximum energy products are lower than 1 MGOe and increase with the second power of the strontium ferrite content. The best maximum energy product and specific saturation magnetization were obtained for the plastoferrite with a 85 weight percentage of ferrite.