Ferrimagnetism in EuFe₄Sb₁₂ due to the Interplay of f-Electron Moments and a Nearly Ferromagnetic Host

We combine x-ray magnetic circular dichroism spectroscopy at Fe L_2,3 edges, at Eu M_4,5 edges, x-ray absorption spectroscopy (XAS) investigation of Eu valence, and local spin density calculations, to show that the filled skutterudite Eu_0.95Fe₄Sb₁₂ is a ferrimagnet in which the Fe 3d moment and the Eu²⁺ 4f moment are magnetically ordered with dominant antiferromagnetic coupling. From Eu L₃ edge XAS, we find that about 13% of the Eu have a formal valence of 3+. We ascribe the origin of ferrimagnetism at a relatively high transition temperature T_C of 85 K in Eu_0.95Fe₄Sb₁₂ to f-electron interaction with the nearly ferromagnetic [Fe₄Sb₁₂]^2.2- host lattice.