Asymmetric Magnetization Reversal in the Exchange-Biased MnO/(Ga,Mn)As Heterostructure Studied by Ferromagnetic Resonance

Abstract

We report ferromagnetic resonance study of the magnetization reversal in the exchange-coupled MnO/(Ga,Mn)As system. The low-field parts of ferromagnetic resonance spectra measured along [110] and [100] directions of (Ga,Mn)As were combined into hysteresis loops, which under field-cooling conditions similarly to SQUID loops are shifted toward negative magnetic fields. The magnetization reversal process revealed by the loops occurred remarkably asymmetric for both sample configurations.