Strongly reduced lattice thermal conductivity in Sn-doped rare-earth (M) filled skutterudites M _x Co₄Sb_12-y Sn _y , promoted by Sb-Sn disordering and phase segregation.

ABSTRACT: CoSb₃ thermoelectric skutterudite has been filled with rare-earth metals (M = La, Ce, Yb) and partially doped with Sn in specimens of M _x Co₄Sb_12-y Sn _y stoichiometry. This has been achieved under high-pressure conditions at 3.5 GPa in a piston-cylinder hydrostatic press. A structural investigation using synchrotron X-ray diffraction data reveals a phase segregation in twin skutterudite phases with filling fraction fluctuation and different unit-cell sizes. As a result of three effects acting as phonon scatterers, namely the rattling effect of M at the wide 8a cages of the cubic Im3̄ structure, the phase segregation, and the intrinsic disorder introduced by Sn substitution at the Sb sublattice, the to

SUBMITTER: Gainza J 

PROVIDER: S-EPMC9037351 | biostudies-literature | 2021 Jul

REPOSITORIES: biostudies-literature