Asymmetric Magnetization Reversal Probed by Recoil Loop Measurements inan Exchange Biased La_0.67Sr_0.33MnO₃/La_0.33Ca_0.67MnO₃ Bilayer Film

We exploit the recoil loop measurements to study the asymmetric magnetization reversal in an exchange-biased La_0.37Sr_0.33MnO₃/La_0.33Ca_0.67MnO₃ bilayer film. It is found that the recoil curve encloses a marked area only in the second quadrant of the hysteresis loop, and the recoil susceptibility in the descending branch of the major loop is evidently higher than that in the ascending branch. The study indicates that the exchange anisotropy of a unidirectional nature and an orientation deviated from the easy axis of the ferromagnetic layer plays a crucial role in creating the reversal asymmetry.