Magnetic phases of thin Fe films grown on stepped Cr(001)

Abstract

Magnetic phases of Fe films grown on curved Cr(001) with steps parallel to [100] are studied using the surface magneto-optic Kerr effect (SMOKE). We found that the atomic steps (1) induce an in-plane uniaxial magnetic anisotropy with the easy magnetization axis parallel to the step edges, and (2) generate magnetic frustration either inside the Fe film or at the Fe-Cr interface, depending on the Fe film thickness and the vicinal angle. For thickness greater than 35 \AA{}, the Fe film forms a single magnetic domain and undergoes an in-plane magnetization switching due to the competition of the step-induced anisotropy and the Fe-Cr interfacial frustration. For thickness less than 35 \AA{}, the Fe film forms multiple magnetic domains at low vicinal angle, and transforms into a single domain at high vicinal angle. A magnetic phase diagram in the 30--45 \AA{} thickness range was obtained using a wedge-shaped Fe film.