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

The structural and magnetic properties of Co-2 MnSi (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 degrees in the (001) 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 CMS[1 (1) over bar0] (GaAs[1 (1) over bar0] direction and a cubic anisotropy with easy axes of CMS < 110 > 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/cm(3) (3.9 mu B/f.u.) at room temperature, a value slightly higher (similar to 7%) than that of the sample without MgO. (c) 2007 Elsevier B.V. All rights reserved.