Epitaxial Growth and Magnetic Properties of Mn-Ga Thin Films on GaSb (001)

摘要

We report on the epitaxial stabilization of tetragonal DO22-type Mn3_dGa (d=0 to 2) films deposited on GaSb(001) by using a molecular beam epitaxy technique. The structural and the magnetic properties as functions of the Mn concentration are discussed. The growth orientation of Mn-Ga(114)//GaSb (001) caused the easy magnetocrystalline direction to be located in the film plane in our experiment, which differed from the ordinarily observed perpendicular magnetic-anisotropy of Mn3-dGa films. The increase in coercivity with increasing temperature for the MnGa film is possibly due to an increase in the anisotropy energy. The MnGa film exhibited an enhanced anisotropy energy with respect to Mn3Ga film. An increasing average saturation magnetization per Mn atom with decreasing Mn content was also observed, indicating a ferrimagnetic ordering with partially compensating moments of the two crystallographically different Mn sites in the DO22 structure.