Strain and magnetic anisotropy of as-grown and annealed Fe films on c(4×4) reconstructed GaAs (001) surface

Abstract

Fe films with the different thicknesses were grown on c(4×4) reconstructed GaAs (001) surfaces at low temperature by molecular-beam epitaxy. Well-ordered bcc structural Fe epitaxial films are confirmed by x-ray diffraction patterns and high-resolution cross-sectional transmission electron microscopy images. A large lattice expansion perpendicular to the surface in Fe film is observed. In-plane uniaxial magnetic anisotropy is determined by the difference between magnetizing energy along [1¯10] and [110] directions, and the constant of interfacial uniaxial magnetic anisotropy is calculated to be 1.02×10−4 J m−2. We also find that magnetic anisotropy is not obviously influenced after in situ annealing, but in-plane strain is completely changed.