Domain structure and magnetization of the permalloy/niobium bilayers

Domain structure and kinetics of the magnetization reversal in the Py/Nb bilayers grown with lift-off lithography have been studied using visualization by magneto-optical indicator film technique. Various types of domain walls and switching behavior are observed depending both on film and substrate thickness. The observed transformations of the domain structure are in agreement with the model, which takes into account effective surface anisotropy governed by surface roughness, while influence of the misfit-induced elastic strain is found to be negligible.