Synthesis and physical properties of a new caged compound Ce3Pd20As6 of the C6Cr23-type structure

摘要

We have found that Ce3Pd20As6 crystallizes into a cubic C6Cr23-typestructure. Combination of electron probe microanalysis of the chemicalcomposition and Rietveld analysis of the powder X-ray diffraction pattern hasrevealed an inhomogeneous atomic composition of variable stoichiometry. Thephysical properties of Ce3Pd20As6 were investigated by measuring themagnetization, electrical resistivity and specific heat. The 4f electrons ofCe3+ ions are well localized but do not show phase transition down to 0.5 K.The metallic electrical resistivity shows a weak Kondo screening. The residualresistivity ratio is rather low probably due to the variable stoichiometry. Themagnetization curve and magnetic entropy suggest the Gamma_8 quartetcrystalline-electric-field ground state at least one of two Ce sites.