R&D: Granular Micromagnetic HAMR Model, Investigation of Damping Dependence and Parametric Optimization for High Performance

Journal of Physics D: Applied Physics has published an article written by W Pantasri, Magnetic Information Storage Technology Research Unit, Department of Physics, Mahasarakham University, Mahasarakham 44150, Thailand, A Meo, Magnetic Information Storage Technology Research Unit, Department of Physics, Mahasarakham University, Mahasarakham 44150, Thailand, and Department of Electrical and Information Engineering, Politecnico of Bari, 70125 Bari, Italy, R W Chantrell, Magnetic Information Storage Technology Research Unit, Department of Physics, Mahasarakham University, Mahasarakham 44150, Thailand, and School of Physics, Engineering and Technology, University of York, York YO10 5DD, United Kingdom, P Chureemart, and J Chureemart, Magnetic Information Storage Technology Research Unit, Department of Physics, Mahasarakham University, Mahasarakham 44150, Thailand.

Abstract: “Heat assisted magnetic recording (HAMR) is a novel high-density magnetic recording technology that relies on thermal assist from a laser during the writing process. To achieve high writing performance, it is important to study and optimize the crucial factors affecting the magnetization reversal mechanism at elevated temperature. In this work, we use a multiscale approach that combines atomistic and micromagnetic models to study the magnetization reversal behavior in the recording medium. The atomistic model allows to parameterize accurately the macroscopic approach, which is utilized to model the system and its dynamics. We perform a parametric investigation of the switching properties as a function of the HAMR setup characteristics as well as the material properties, such as magnetic damping. The results show that high damping and moderate external fields can achieve high-performance HAMR media characterized by high switching probability, short switching time and low peak temperature. We demonstrate that switching occurs via the linear reversal mechanism. By systematic variation of the longitudinal susceptibility we force a transition to coherent reversal and demonstrate that this reduces the switching probability, showing linear reversal to be an important component within the HAMR process.“