Nonswitchable magnetic moments in polycrystalline and (111)-epitaxial permalloy/CoO exchange-biased bilayers

We have measured the interfacial magnetization depth profile in ferromagnet/antiferromagnet exchange-coupled NiFe/CoO bilayers. Both a polycrystalline and an epitaxial-(111) bilayer were examined. We find that the nonswitchable magnetization profile in the biased state is highly correlated with the magnetization profile in the unbiased state. The nonswitchable moment distributions are shown to be consistent with the predictions of a previously reported model for the magnetic and microstructural features of the interfacial region.