Epitaxial growth and characterization of Co2MnSi thin films on GaAs with MgO interlayer

The structural and magnetic properties of Co2MnSi (CMS) thin films epitaxially grown on GaAs substrates by sputtering were investigated. The CMS film directly grown on GaAs showed a cube-on-cube crystallographic relation, while it was rotated by 45° in the (0 0 1) plane when a thin MgO layer was inserted between the CMS and GaAs. The CMS film directly grown on GaAs showed strong magnetic anisotropy consisting of a uniaxial anisotropy with an easy axis of CMSView the MathML source (GaAsView the MathML source) direction and a cubic anisotropy with easy axes of CMS〈1 1 0〉 directions. The uniaxial anisotropy was weakened in the samples with a MgO interlayer. The magnetization value of the CMS film with a 3.0-nm-thick MgO was approximately 820 emu/cm3 (3.9μB/f.u.) at room temperature, a value slightly higher (∼7%) than that of the sample without MgO.