Raman scattering study of antimony-based skutterudites

Raman spectra of single-crystal CoSb3 and RhSb3 and of polycrystalline IrSb3 have been studied. We have also studied four different polycrystalline-filled skutterudite samples, Ir4LaGe3Sb9, Ir4NdGe3Sb9, Ir4SmGe3Sb9, and Fe4CeSb12, where rare-earth ions occupy the voids in the skutterudite structure. These void-filling ions interact with some of the lattice vibrations in this structure and produce a shift and broadening of the observed lines. The most prominent lines in all of the samples are the Sb-4 ring-breathing modes. (C) 1996 American Institute of Physics.