Strongly reduced lattice thermal conductivity in Sn-doped rare-earth (M) filled skutterudites M x Co 4 Sb 12- y Sn y , promoted by Sb-Sn disordering and phase segregation.

Autor: Gainza J; Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC), Sor Juana Inés de la Cruz 3 E-28049 Madrid Spain j.gainza@csic.es ja.alonso@icmm.csic.es., Serrano-Sánchez F; Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC), Sor Juana Inés de la Cruz 3 E-28049 Madrid Spain j.gainza@csic.es ja.alonso@icmm.csic.es., Nemes NM; Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC), Sor Juana Inés de la Cruz 3 E-28049 Madrid Spain j.gainza@csic.es ja.alonso@icmm.csic.es.; Departamento de Física de Materiales, Universidad Complutense de Madrid E-28040 Madrid Spain., Dura OJ; Departamento de Física Aplicada, Universidad de Castilla-La Mancha Ciudad Real E-13071 Spain., Martínez JL; Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC), Sor Juana Inés de la Cruz 3 E-28049 Madrid Spain j.gainza@csic.es ja.alonso@icmm.csic.es., Fauth F; CELLS-ALBA Synchrotron Cerdanyola del Valles Barcelona E-08290 Spain., Alonso JA; Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC), Sor Juana Inés de la Cruz 3 E-28049 Madrid Spain j.gainza@csic.es ja.alonso@icmm.csic.es.
Jazyk: angličtina
Zdroj: RSC advances [RSC Adv] 2021 Aug 03; Vol. 11 (42), pp. 26421-26431. Date of Electronic Publication: 2021 Aug 03 (Print Publication: 2021).
DOI: 10.1039/d1ra04270j
Abstrakt: CoSb 3 thermoelectric skutterudite has been filled with rare-earth metals (M = La, Ce, Yb) and partially doped with Sn in specimens of M x Co 4 Sb 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 8 a cages of the cubic Im 3̄ structure, the phase segregation, and the intrinsic disorder introduced by Sn substitution at the Sb sublattice, the total thermal conductivity ( κ ) dramatically falls to reach minimum values under 2 W m -1 K -1 , well below those typically exhibited by other thermoelectric materials based upon single-filled skutterudites. The power factor is substantially enhanced to 1.11 mW m -1 K -2 in Yb 0.5 Co 4 Sb 11.6 Sn 0.4 with respect to the unfilled composition, as a result of the charge transfer promoted by the filler.
Competing Interests: There are no conflicts to declare.
(This journal is © The Royal Society of Chemistry.)
Databáze: MEDLINE
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