Initial Layer Model for d$M$/d$H$Anomaly at 0-Field of In-Plane Magnetization in Perpendicular Recording Media

Abstract

To evaluate properties of an initial growth layer for CoCrPt-SiO 2 perpendicular recording media, an initial growth layer has been investigated by micromagnetic simulation with initial layer model. It was found that with the initial growth layer, the in-plane magnetization Min shows a small jump at 0-field, leading to an additional peak around 0-field in 4 pi dMin/dH curve. The (additional) peak height increases with the increase in inter- lower subgrain exchange areal energy densities wi and thickness of the initial layer and also decreases in the anisotropy energy for the initial layer. Considering the change of the average anisotropy energy as a function of the thickness of recording layer, wi for a CoCrPt-SiO2 perpendicular recording medium with Ru/Ru-SiO2 intermediate layer is in the range from 0.5 to 0.6 erg/cm2 and roughly 30% smaller than those with a Ru intermediate layer