Magnetism of pristine Fe films on GaAs(100)

We grew Fe films on GaAs(100) at similar to 80 K to suppress interface alloying and As outdiffusion, and obtained kinetically stabilized, pristine Fe films. We studied their magnetic properties using both x-ray magnetic circular dichroism and the magneto-optic Kerr effect. The salient magnetic features are as follows. A 2.1-ML-thick Fe film is already ferromagnetic and exhibits perpendicular magnetic anisotropy (PMA). Moreover, a spin reorientation transition occurs in films with similar to 2.8 monolayer thickness. The PMA is attributable to preservation of the surface magnetic anisotropy by suppressing the As outdiffusion during the low-temperature growth of the Fe film. The PMA is associated with the enhancement of the orbital moment by only similar to 50% in contrast to values reported in some previous studies.