Enhanced magnetic orbital moment of ultrathin Co films on Ge(100)

Electronic and magnetic studies of Co films grown on Ge(100) are presented using two sample systems; incremental in situ Co depositions and a pre-made Co wedge structure. Both a magnetically inactive region and a corresponding Co-Ge intermixed region form at the interface of both systems. The Co grows in a uniform manner beyond this Co-Ge region with ~2 perpendicular roughness. At low coverage of the in situ grown system, the Co exhibited an enhanced orbit to spin moment ratio, while, at higher Co coverages, we measured a total magnetic moment of 1.53μB in agreement with previously published results of bcc Co grown on GaAs. The Co wedge indicated a constant but larger orbit-spin ratio along the wedge possibly due to the presence of an overlayer.