  Epitaxial growth of Co20Fe50Ge30 thin film on single crystal MgO (001)
substrate is reported. Structure characterization revealed (001)-oriented B2
order of CoFeGe well lattice matched with the MgO barrier. Perpendicular
magnetic anisotropy (PMA) was achieved in the MgO/CoFeGe/MgO structure with an
optimized magnetic anisotropy energy density (K) of 3 106 erg/cm3. The magnetic
anisotropy is found to depend strongly on the thickness of the MgO and CoFeGe
layers, indicating that the PMA of CoFeGe is contributed by the interfacial
anisotropy between CoFeGe and MgO. With reported low damping constant, CoFeGe
films are promising spintronic materials for achieving low switching current.
