Transverse field-induced magnetization process in an ultrathin Au/Co/Au film

The in-plane (transverse) H∥ field-induced magnetization reversal process in a polycrystalline Au/Co/Au ultrathin magnetic film structure with strong perpendicular anisotropy has been studied. Faraday rotation microscopy shows that the domain structure, initially prepared under an H⊥ field, is not influenced under H∥. Only the value of the net perpendicular magnetization inside the domains is reduced. Our data are described in the frame of a simple model which assumes that the sample is composed of nanometer-sized uncoupled atomic terraces (patches) with different local anisotropies. The limits of our model are discussed.