Anisotropic lattice relaxation and uniaxial magnetic anisotropy in Fe/InAs(100)-4x2

The magnetic anisotropy and the lattice relaxation of epitaxial Fe films gr own on InAs(100)-4 X 2 at room temperature have been studied using in situ magneto-optical Kerr effect and reflection high-energy electron diffraction . The experimental results demonstrate that the symmetry breaking associate d with the intrinsic atomic scale structure of the reconstructed semiconduc tor surface induces an in-plane anisotropic lattice relaxation and an in-pl ane uniaxial magnetic anisotropy in the ultrathin region. We propose that t his is a general phenomenon in ferromagnetic/semiconductor heterostructures .