EPITAXIAL STRUCTURE AND MAGNETIC ANISOTROPIES OF METASTABLE SINGLE-CRYSTAL CO0.70MN0.30 FILM

Alloy films of Co0.70Mn0.30 were grown on GaAs (001) substrates by mol ecular beam epitaxy at room temperature. The metastable tetragonally d istorted single crystal structure was confirmed by reflection high ene rgy electron diffraction and x-ray diffraction measurement, which exhi bited a 2.87 Angstrom in-plane lattice parameter. Ferromagnetic resona nce measurements and theoretical fitting were performed and showed tha t, with a Mn capping layer, a uni-directional anisotropy existed. In a ddition, a fourfold tetragonal magnetocrystalline anisotropy as well a s a uniaxial term in the film plane was also confirmed. The hysteresis loops recorded by longitudinal magneto-optical Kerr-effect also demon strated the existence of different kinds of in-plane magnetic anisotro py. The origins of the anisotropy are explained tentatively. (C) 1997 American Institute of Physics.