Molecular-beam epitaxy of Co2MnSiCo2MnSi Heusler alloy thin films epitaxially grown on Si(0 0 1)

We report on the investigation of structural and magnetic properties of the ternary Heusler alloy Co2MnSiCo2MnSi grown on Si(0 0 1) by molecular-beam epitaxy. Low-energy electron diffraction (LEED), inelastic medium-energy electron diffraction (IMEED) and X-ray photoelectron diffraction (XPD) measurements clearly show the growth of crystalline Co2MnSiCo2MnSi. The best crystallographic and magnetic quality of the Co2MnSiCo2MnSi films have been achieved after codeposition of the three Co, Mn and Si elements on the Si(0 0 1) substrate held at 587 K. Quantitative determinations of magnetic anisotropies were performed using transverse bias initial inverse susceptibility and torque measurements (TBIIST). Co2MnSiCo2MnSi reveals to have an in-plane fourfold magnetocrystalline anisotropy with easy axis along 〈010〉 directions for evaporation fluxes perpendicular to the substrate surface. On the other hand, grazing-incidence fluxes invariably generate a dominant uniaxial in-plane magnetic anisotropy contribution with easy axis perpendicular to the incidence plane.