Annealing effect on the recovery of training effect in FeOx-CoFe polycrystalline systems

Recovery, by low-temperature (70°C) annealing, of switching fields and training effect of a trained FeO_x(α-Fe₂O₃ with a fraction of Fe_0.98O)(70 nm)-CoFe(5 nm) bilayer sample has been investigated. The recovery curve of the switching field in the direction opposite to the pinned direction was well fitted to a curve of a single activation energy response curve for about 1 eV. The training effect was also found to recover by annealing to some extent, but not as much as the switching field. Those results have been explained by a different mechanism from the thermal spin-flip mechanism contributing to the training effect itself.