Magnetic domains in thin epitaxial Co/Au(111) films.

The formation of magnetic domains in thin epitaxial Co/Au(111) films is investigated. Three-monolayer films are shown to decay into out-of-plane domains of micron size. We find a smooth transition from out-of-plane to in-plane magnetization at a crossover thickness of 4.5 layers and determine that the domain size depends linearly on film thickness below crossover.