Itinerant and local magnetic moments in ferrimagnetic Mn2CoGa thin films probed by x-ray magnetic linear dichroism: experiment and ab initio theory

Epitaxial thin films of the half-metallic Xa-compound Mn2CoGa (Hg2CuTi prototype) were prepared by dc magnetron co-sputtering with different heat treatments on MgO (001) substrates. High-quality films with a bulk magnetization of 1.95(5)\mu_B per unit cell were obtained. The L3,2 x-ray magnetic circular dichroism spectra agree with calculations based on density functional theory (DFT) and reveal the antiparallel alignment of the two inequivalent Mn moments. X-ray magnetic linear dichroism, in good agreement with theory as well, allows to distinguish between itinerant and local Mn moments. Based on non-collinear spin DFT it is shown that one of the two Mn moments has local character, whereas the other Mn moment and the Co moment are itinerant.