A Coercivity Measuring Method of Barium Ferrote Fome Powder for Particulate Perpendicular Magnetic Recording Media

A Barium ferrite platelet fine particle coercive force is affected by magnetic particle agglomeration. Investigations of a new measuring method to determine the intrinsic coercive force of Ba-ferrite particles that exclude the effect of magnetic agglomeration are reported. The new method was to make coercive force measurements for Ba-ferrite particles dispersed and attached on large SiO2 particle surfaces. Coercive force measurement for samples of low Ba-ferrite/SiO2 mixing ratio confirmed that it was possible to measure the intrinsic coercive force excluding the influence of magnetic agglomeration.