Tatsumi Maeda

Relationship Between Particle Volume and Saturation Magnetization on Ba-Ferrite Fine Powder

I. Purpose Saturation magnetization of hexagonal platelet Ba-ferrite fine particles, for use in particulate perpendicular magnetic recording media, decreases with increasing specific surface area, in particular with increasing c-plane component of specific surface area of particles [1,2]. We reasoned that this is probably caused by the existence of a nonferromagnetic layer on the c-plane surfaces of the platelet particles [2]. However, it is known that as the volume of fine magnetic powders diminishes and the proportion of very fine particles increases, the thermal fluctuation effect