Epitaxial Growth of Full-Heusler Alloy Co₂MnSi Thin Films on MgO-Buffered MgO Substrates

Full-Heusler alloy Co2MnSi (CMS) thin films were epitaxially grown on MgO-buffered MgO substrates through magnetron sputtering. The films were deposited at room temperature and subsequently annealed in situ at 600degC. X-ray pole figure measurements of the annealed films showed 111 peaks with fourfold symmetry, providing direct evidence that these films were epitaxial and crystallized in the L21structure. The annealed films had sufficiently flat surface morphologies with root-mean-square roughness of about 0.22 nm at a film thickness of 50 nm. The saturation magnetization of the annealed films was 4.5muB/f.u. at 10 K, corresponding to about 90% of the Slater-Pauling value for CMS