Field and Temperature-Driven Magnetic Reversal of Spin-flop Coupled Epitaxial Fe/MnPd Bilayers

We studied field and temperature-driven magnetic reversal of epitaxial spin-flop coupled Fe/MnPd bilayers. The onset temperatures for the spin-flop coupling, the loop shift, and the reversal asymmetry were found to be different for the same sample, indicating their sensitivity to different interface components. We show that the induced uniaxial anisotropy is a direct result of the spin-flop coupling, while the loop shift, observed along the bias, and the reversal asymmetry, measured perpendicular to the bias, are likely relevant to the local pinning environments and the remanence state of the ferromagnet. Further, the unidirectional bias can be manipulated by a controlled recooling process, while keeping the spin-flop property unaffected. Finally, we experimentally reveal the temperature-driven magnetization transitions in the thermal hysteresis of the bilayers and demonstrate the important role of competing energy terms on the observation of different types of thermal hysteresis behaviors.