Static and dynamic magnetic properties of epitaxial Fe1.7Ge thin films grown on Ge(111)

Abstract

We have studied the magnetic properties of thin epitaxial hexagonal Fe1.7Ge films grown on Ge(111) substrates by molecular beam epitaxy. For all samples, X-ray diffraction revealed an excellent epitaxy of the Fe1.7Ge films, with crystallographic [112¯0] and [11¯00] axes lying in the sample plane. The static magnetic properties were studied by Magneto-Optical Kerr Effect (MOKE) at room temperature. The dynamic magnetic properties at room temperature were investigated by Micro-Strip Ferromagnetic Resonance (MS-FMR). The frequency dependence of the spectra versus the orientation of the applied in-plane magnetic field shows that the contribution of the in-plane anisotropy to the magnetic energy density consists in two distinct terms exhibiting a twofold and a sixfold symmetry, respectively. The amplitude of the sixfold anisotropy constant is an increasing function of the film thickness. The observed angular dependence of the MOKE reduced remanent magnetization is described using a coherent rotation model. A good agreement is observed between the in-plane anisotropy values derived from MS-FMR and those obtained with MOKE Transverse Bias Initial Inverse Susceptibility and Torque data.