Investigation of ferromagnetic filled skutterudite compounds EuT4Sb12 (T = Fe, Ru, Os)

The physical properties of single crystals of filled skutterudite compounds EuT4Sb12 (T = Fe, Ru, Os) have been investigated by means of x-ray diffraction, electrical resistivity, specific heat, magnetization, and x-ray absorption spectroscopy measurements. The Eu-based materials crystallize in the LaFe4P12-type structure (space group ). A small Eu deficiency is encountered for Eu0.95Fe4Sb12, while the homologous compounds, Eu1.0Ru4Sb12 and Eu1.0Os4Sb12, reveal full occupancy of the Eu site. Eu0.95Fe4Sb12 appears to exhibit either canted ferromagnetic or ferrimagnetic order at TC = 88 K whereas EuRu4Sb12 and EuOs4Sb12 are ferromagnets with Curie temperatures of TC = 4 and 9 K, respectively. X-ray absorption near edge spectroscopy measurements reveal a nearly divalent Eu electronic configuration for EuT4Sb12 (T = Fe, Ru, Os) with no significant change with T atom or temperature.