In situ multifrequency ferromagnetic resonance and x-ray magnetic circular dichroism investigations on Fe/GaAs(110): Enhanced g-factor

We determined the magnetic anisotropy energy and g-factor of an uncapped 10 nm thick Fe/GaAs(110) film using a setup that allows frequency (1.5–26.5 GHz) as well as angular dependent ferromagnetic resonance measurements under ultrahigh vacuum conditions. The g-factor g=2.61±0.1 is unusually high at room temperature and can be interpreted as the result of an increased orbital moment due to strain. This interpretation is supported by more surface sensitive x-ray magnetic circular dichroism measurements which yield g=2.21±0.02 measured at remanence. The difference in g may be the result of magnetic field dependent magnetostriction which influences the orbital moment.