Ferromagnetic domain structure and hysteresis of exchange bias in NiFe/NiMn bilayers

Magnetization reversal in NiFe/NiMn bilayers was studied by measuring anisotropic magnetoresistance and pseudo-Hall effect simultaneously. Since the single domain state of the ferromagnetic layer could be well traced in such measurements, we were able to distinguish hysteresis of exchange bias from inhomogeneous magnetization. The exchange bias was found to have two components during the single domain reversal process. Domain breaking in given fields took place when the biasing field became more random.