Interface magnetism in epitaxial Fe/InAs heterostructures

Abstract

Abstract-The growth and interface magnetic properties of epitaxial Fe films grown on InAs (100)-4 2 have been studied using low-energy electron diffraction, in situ magneto-optical Kerr effect, and X-ray magnetic circular dichronism. The magnetic properties at room temperature were found to proceed via three phases with thickness; a nonmagnetic phase, a superparamagnetic phase, and a ferromagnetic phase. The initial ferromagnetic phase might be stabilized by interparticle interactions. The films show bulk-like spin moments of 1.90 0.15 with the thickness above about 20 ML and a large enhancement 260% of the ratio of orbital versus spin moment in the ultrathin region.Index Terms-Fe-InAs, interface magnetism, spin electronics, ultrathin films.

Mesoscopic Magnetic/Semiconductor Heterostructures

“…The superparamagnetic phase forms in a narrow thickness range of 3.5-4.8 ML for Fe/GaAs and 2.5-3.8 ML for Fe/InAs, respectively [5], [8]. The exchange interaction within these clusters leads to internal ferromagnetic ordering, thus giving rise to the well-known superparamagnetic phase.…”