MBE growth of single crystal α-Fe films on ZnSe (001) and (110)

Abstract

We report the growth by molecular beam epitaxy oh high quality single crystal films of ferromagnetic α-Fe on ZnSe (001) and (110) epilayers grown on chemically etched and annealed GaAs wafers. The films were characterized by reflection high energy electron diffraction (RHEED), Auger electron spectroscopy (AES), X-ray diffraction (θ-2θ), ferromagnetic resonance (FMR) and vibrating sample magnetometry. RHEED demonstrates single crystal Fe film growth in registry with the ZnSe surface, and indicates that the surface order of the Fe (110) films is superior to that of the Fe (001) films. The FMR linewidth and measured coercive fields are significantly smaller than previously reported for similar Fe films grown directly on the GaAs substrates. Room temperature FMR spectra (35 GHz) of thin Fe (001) films (∼140 Å) exhibit symmetric Lorentzian lineshapes with a linewidth of 45 Oe, which represents the narrowest 35 GHz FMR linewidth ever measured in single crystal iron, and approaches the theoretical lower limit set by Landau-Lifschitz broadening.