Investigating Magnetocrystalline Anisotropy in the System Au/Co-Staircase/Au(788) by Using XMCD

Here, we report the investigation of the influence of the magnetocrystalline anisotropy (MCA) in Cobalt ultrathin films grown on the vicinal surface Au(788), through the anisotropy of the orbital magnetic moment. The aim of this study was to apply the X-ray magnetic circular dichroism (XMCD) technique to probe the spin magnetic moment and the orbital magnetic moment anisotropy within the spin reorientation transition (SRT) range in the system Au/Co-Staircase/Au(788). The influence of increasing Co film thickness on SRT, from easy out-of-plane magnetization axis to in-plane magnetization was investigated by means of the magneto-optical Kerr effect (MOKE). The preparation and surface quality of the Co films were characterized using low energy electron diffraction (LEED) and scanning tunneling microscopy (STM). Analysis of XMCD measurements as a function of the film thickness for Au/Co-staircase/Au(788) reveals the anisotropic orbital magnetic moment during the SRT regime (8-12 ML range) indicating a decreasing influence of MCA with the increased thickness and nearly isotropic orbital magnetic moment above 12 ML, with a small MCA influence.