The Influnence of the Amplitude and Frequency of Sweeped Magnetic Field on the Exchange Bias and Coercivity for Ferromagnetic / Antiferromagnetic Films: Monte Carlo Simulation

Abstract

The influnence of the amplitude (H0) and frequency of sweeped magnetic field on the exchange bias He and coercivity Hc for ferromagnetic/ antiferromagnetic films has been simulated with Monte Carlo method. In a cycle, the sweeped frequency is inversely proportional to Monte Carlo steps (MCSs). It is observed that, for smaller MCSs, the values of He and the blocking tempreture Tb reduce evidently with increasing MCSs; for larger MCSs, the values of He and Tb decrease gently with increasing MCSs. It is also found the values of He and Tb decrease obviously with increasing values of H0 (HN0). However, on the contrary, the value of Hc increases with increasing values of H0 (HN0). At low temperature and little HN0, the asymmetric loop may appear, which is attributed to the competition between the relaxation time and the period of the external magnetic field. Moreover, the symmetry of the loops influences evidently the values of He and Hc.