Solid state reaction synthesis of filled skutterudite compounds (Ce or Y)(y)FexCo4-xSb12 and the effect of filling atoms Ce or Y on lattice thermal conductivity

The synthesis of filled skutterudite compounds (Ce or Y)(y)FexCo4-xSb12, th rough a solid state reaction using chloride of Ce or Y, high purity powder of Co, Fe, and Sb as starting materials, was investigated. (Ce or Y)(y)FexC o4-xSb12 (x = 0-1.0, y = 0-0.15) compounds were obtained at 850-1 123 K. Th e results of Rietveld analysis demonstrate that (Ce or Y)(y)FexCo4-xSb12 sy nthesized by a solid state reaction possesses a filled skutterudite structu re. The filling fraction of Ce or Y obtained by Rietveld analysis agrees we ll with the composition obtained by chemical analysis. The lattice constant of CeyFexCo4-xSb12 increases with increasing substitution of Fe at Co site s. and with an increasing Ce filling fraction in the Sb-dodecahedron voids. The lattice thermal conductivity of (Ce or Y)(y)FexCo4-xSb12 decreases sig nificantly with an increasing Ce or Y filling fraction in the voids and wit h substitution of Fe at Co sites.