The Hysteretic Behavior of Angular Dependence of Exchange Bias in NiFe/granular-FeMn-MgO Bilayers

We investigate the hysteretic behavior of the angular dependence of exchange bias for a series of polycrystalline NiFe/（FeMn）1-x（MgO）x bilayers with varying x.For x = 0.025,the antiferromagnetic layer is of the largest degree-of the fcc（111） preferred texture.At the same x,both the exchange field and blocking temperature acquire maximal values.In particular,the hysteretic behavior of the angular dependence between clockwise and counter-clockwise rotations shows minimal angular shift.These results can be explained in terms of the thermal activation model.