SUBSTITUTION EFFECTS ON THE CHARACTERISTICS OF Ba FERRITE PARTICLES

概要

論文の詳細を見る
By investigating substitution effects on the properties of Ba ferrite particles for magnetic recording media, it has been found that Zn substituted particles have a rather small SFD(switching field distribution) compered with Co substituted particles. In particular, Co-Zn-Nb substituted Ba ferrite particles with a small amount of Co and a large amount of Zn are promising materials, exhibiting a small SFD and a small temperature coefficient of coercivity. The Zn-rich parricles have been found by torque measurement to be single-domain particles and have a uniaxial magnetocrystalline anisotropy not only at room temperature but also at low temperature. The Zn-rich particles have a small K2 in comparison with K1, while Co-rich particles have a comparatively large K2, especially at low temperature. From these results, it can be said that the Zn-rich particles have an idial uniaxial magnetocrystalline anisotropy. By the measurement of rotational hysteresis integral and angular depedance of coercivity, it has been found that the magnetization reversal for a medium using the Zn-rich particles is incoherent but more coherent than for a medium using Co-rich particles. It has been found that recording media using the Zn-rich particles of Co-Zn-Nb substitution system exhibiting a small SFD show excellent recording performance, especially in a short wavelength range.
社団法人日本磁気学会の論文