Study of Thermal Hysteresis in FeRh Films Under Fast Temperature Modulation of the Phase Transition

The thermal hysteresis exhibited by FeRh thin films under fast temperature driving is studied using a modulated reflectance setup. The antiferromagnetic/ferromagnetic (AF/FM) phase fraction modulation, driven by a pump-laser induced square-modulated periodic temperature change, is used to investigate the transition kinetics, and the associated thermal hysteresis. While the compliance with return-point-memory (RPM) is verified on the average, time resolved measurements of the modulated AF/FM fraction show, within certain temperature intervals, a complex stochastic behavior where randomly triggered phase changes define the way the material memory is stored, and erased.