Analysis of disordered stripe magnetic domains in strained epitaxial Ni(001) films

The disordered stripe domain structures in strained epitaxial Ni(001) films with film thickness ranging from 10 to 220 nm have been studied by magnetic force microscopy. A theoretical model of periodic stripe domain structures with tilted partial flux closure domains has been successfully applied to describe the features of these domain structures. The model predicts that the thinnest films (t<25nm) show no flux closure domains whereas thicker films have a significant volume fraction ({~}40%) of flux closure domains with the tilt angle varying continuously from being normal to the film's surface to parallel to the surface with increasing film thickness. The tilt of the moments in the flux closure domains correspondingly gives rise to an in-plane magnetization, in accordance to the experimental observation in these Ni films.