  We have studied the magnetization reversal process in FM/AFM bilayer
structures through of spin dynamics simulation. It has been observed that the
magnetization behavior is different at each branch of the hysteresis loop as
well as the exchange-bias behavior. On the descending branch a sudden change of
the magnetization is observed while on the ascending branch is observed a bland
change of the magnetization. The occurrence of the asymmetry in the hysteresis
loop and the variation in the exchange-bias is due to anisotropy which is
introduced only in the coupling between ferromagnetic (FM) and
antiferromagnetic (AFM) layers.
