Growth, structural, and magnetic characterization of epitaxial Co2MnSi films deposited on MgO and Cr seed layers

We report detailed structural characterization and magneto-optical Kerr magnetometry measurements at room temperature in epitaxial Co2MnSi thin films grown on MgO(001) and Cr(001) buffered MgO single crystals prepared by sputtering. While Co2MnSi/Cr//MgO(001) films display the expected cubic anisotropy, the magnetization curves obtained for Co2MnSi//MgO(001) samples exhibit a superimposed in-plane uniaxial magnetic anisotropy. The evolution of magnetization with film thickness points to a relevant interfacial Co2MnSi-buffer layer (Cr or MgO) contribution which competes with magnetic properties of bulk Co2MnSi, resulting in a drastic change in the magnetism of the whole sample. The origin of this interfacial magnetic anisotropy is discussed and correlated with our structural studies.