IrMn Thickness Dependence of Exchange Bias Training Effect in CoFe/IrMn Thin Films

The IrMn thickness dependence of exchange bias training effect was studied in exchange coupled CoFe/IrMn(t ) thin films. The exchange bias training effect was dominated in the range of 3 nm < t < 7 nm. The range was correspond to increasing the exchange bias by the pinned IrMn and decreasing the coercivity by the irreversible behavior of unpinned IrMn based on single domain model. Thus the exchange bias training effect was explained by the relaxation process by the reorientation of pinned-unpinned IrMn from initial alignment to final equilibrium state during the consecutive cycles of M-H loop.