Abstract
The study on temperature dependence of exchange bias field and coercivity is crucial to solving the writ-ing/reading dilemma in magnetic recording.Motivated by recent experimental findings,a complete switch between exchange bias field and coercivity with temperature is proposed,and the performance,charac-terized by average switching temperature(Ts)and switching temperature width(ΔTw),controlled by antiferromagnetic anisotropy(KAF)and exchange coupling(JAF)constants is studied based on a Monte-Carlo simulation.The results show that a linear relationship between Ts and KAF is established when KAF is above a critical value,while Ts is weakly influenced by JAF.On the contrary,ΔTw is insensi-tive to KAF,while strongly depends on JAF.Besides overcoming thermal energy,the increase of KAF for a small JAF guarantees the completely frozen states in the antiferromagnetic layers during magnetizing at higher temperature,below which the exchange bias field exists with a negligible coercivity.Otherwise,for a large JAF,the uncompensated antiferromagnetic magnetization behavior during the ferromagnetic magnetization reversal becomes complicated,and the switching process in the low temperature range depends on the irreversibility of uncompensated antiferromagnetic magnetization reversal during mag-netizing,while in the high temperature range mainly influenced by the field-cooling process,resulting in a large ΔTw.This work provides an opportunity to control/optimize the performance of the temperature-induced switch between unidirectional and uniaxial symmetries through precisely tuning KAF and/or JAF to meet different application demands in the next generation information technology.
基金项目
国家自然科学基金(11774045)
Joint Research Fund Liaoning-Shenyang National Laboratory for Materials Science(20180510008)
NETL
NSTL
维普
万方数据