ANISOTROPY STUDIES ON MOLECULAR-BEAM-EPITAXY-GROWN CO(111) THIN-FILMSBY FERROMAGNETIC-RESONANCE

ne magnetic anisotropy of Co/Cu(111) thin films has been investigated using the ferromagnetic resonance (FMR) technique. The films were prep ared by molecular-beam epitaxy in ultrahigh vacuum on sapphire substra tes with niobium as a buffer layer. In situ RHEED investigations, ex s itu x-ray low-angle reflectivity measurements, and high-angle Bragg sc ans confirm the structural quality of the films. Angular dependent FMR measurements are performed in the plane of the films and out-of-plane . The angular dependence of the line positions in-plane shows a compet ition between the sixfold anisotropy, which is expected for bulk Co, a nd a twofold anisotropy contribution. It is demonstrated that by FMR o ne can detect even small values of the higher-order anisotropy terms. In the analysis, we put emphasis on the relationship between magnetic and structural properties.