R&D: Studies of HAMR Recording by Hybrid Monte Carlo Micromagnetics

IEEE Transactions on Magnetics has published an article written by Jingyue Miao, Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China, and Dan Wei, Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China, and College of Physics and Electronic Information, Inner Mongolia Normal University, Hohhot 011517, China.

Abstract: “The heat-assisted magnetic recording (HAMR) has been studied extensively for its application in extremely high-density hard disk drives. In this paper, we utilize the hybrid Monte Carlo micromagnetics to investigate the HAMR write process and the recording performances by evaluating the signal-to-noise ratio (SNR). The simulation results show that, recording on granular FePt-C media with a grain size (D) ~ 4 nm, the medium SNR drops to 8.36 dB with areal density reaching to ~ 4 Tbit/in². Furthermore, the effects of grain size distribution and Curie temperature (Tc) distribution on HAMR recording are introduced in our simulation considering the sputter conditions in experiments. We build up HAMR recording models by varying grain size distribution and Tc distribution and find out that the effect of the Tc distribution is much stronger than the grain size distribution. With σ Tc/Tc = 0.037 (σD/D = 0.09), the SNR decreases from 15.14 to 12.72 dB while the SNR decreases to 15.01 dB with σD/D rising from 0.09 to 0.15 (σ Tc/Tc = 0).“