Effect of layer thickness ratio on magnetization reversal process in stacked media with high coercivity

Abstract

Effect of thickness ratio and interlayer exchange coupling on time-evolutional magnetization reversal process in stacked media with high coercivity was investigated by utilizing micromagnetic simulation. Regardless of the layer thickness ratio, for each stacked medium the magnetization reversal process is divided into three regions, namely the spin-flop rotation, the incoherent rotation and the coherent rotation along with increase of the interlayer exchange coupling constant Ainterlayer. In order to get the incoherent rotation region which is suitable for the recording media, it is required that the Ainterlayer is between about 1.3×10-7 and 2.2×10-7 erg/cm for the media with the layer thickness ratio of 1 : 3 and 3 : 1, and that one is between about 1.8×10-7 and 2.5×10-7 erg/cm for the media with the ratio near 1 : 1.