Dependence of recorded bit-patterns on saturation magnetization in microwave assisted magnetic recording

Signal recording processes were simulated using micromagnetic calculation for microwave assisted magnetic recording in perpendicular magnetic media. Strong magnetostatic field caused by the large saturation magnetization of the media tends to deteriorate recorded bit patterns resulting in low signal to noise ratio for the play back signal. The moderate exchange interaction fields were shown to improve recording characteristics and increase signal to noise ratio even for the large saturation magnetization media. The influence of thermal fluctuation fields on recording characteristics was also discussed and the influence was negligible for the media assumed in this study.