ASYMMETRY OF DOMAIN NUCLEATION AND ENHANCED COERCIVITY IN EXCHANGE-BIASED EPITAXIAL NIO NIFE BILAYERS/

Magnetization reversal processes in epitaxial NiO/NiFe bilayers were s tudied using the magneto-optic indicator film technique. The influence of dislocations on these processes was determined. Remagnetization pa rallel to the unidirectional anisotropy axis proceeds by domain nuclea tion and growth, with nucleation center activity being asymmetric with respect to the applied field sign. Magnetization reversal in the hard axis direction occurs by incoherent rotation. The enhanced coercivity and asymmetric nucleation can be explained by taking into account dom ain wall behavior in the antiferromagnetic layer.