Magnetic domain formation in Fe films on Cr(100)

Magnetic domain images of thin (2 nm) Fe films on Cr(100) are presented. Upon cooling a single-domain state transforms into a state with a locally varying in-plane magnetization direction. This transformation is partially reversible and highly reproducible. It is suggested that the in-plane rotation is driven by frustration that favors 90 degrees coupling, and that the local magnetization direction reflects mu m-scale variations of the atomic scale roughness.