Disentangling the Mn moments on different sublattices in the half-metallic ferrimagnet Mn_3-xCo_xGa

Ferrimagnetic Mn3-xCoxGa compounds have been investigated by magnetic circular dichroism in x-ray absorption (XMCD). Compounds with x>0.5 crystallize in the CuHg2Ti structure. A tetragonal distortion of the cubic structure occurs for x <= 0.5. For the cubic phase, magnetometry reveals a linearly increasing magnetization of 2x Bohr magnetons per formula unit obeying the generalized Slater-Pauling rule. XMCD confirms the ferrimagnetic character with Mn atoms occupying two different sublattices with antiparallel spin orientation and different degrees of spin localization and identifies the region 0.6<x <= 0.8 as most promising for a high spin polarization at the Fermi level. Individual Mn moments on inequivalent sites are compared to theoretical predictions. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3592802