| Autor: |
Rodrigues JEFS; Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, E-28049 Madrid, Spain.; European Synchrotron Radiation Facility, ESRF, 71 Avenue des Martyrs, 38000 Grenoble, France., Gainza J; Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, E-28049 Madrid, Spain., Serrano-Sánchez F; Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, E-28049 Madrid, Spain., Ferrer MM; CCAF, PPGCEM/CDTec, Federal University of Pelotas, CEP 96010-610 Pelotas, Rio Grande do Sul, Brazil., Fabris GSL; Materials Science and Engineering Postgraduate Program, Department of Materials Engineering, Federal University of Rio Grande do Norte, 59078-970 Natal, Brazil., Sambrano JR; Modeling and Molecular Simulation Group, São Paulo State University, 17030-360 Bauru, SP, Brazil., Nemes NM; Departamento de Física de Materiales, Universidad Complutense de Madrid, E-28040 Madrid, Spain., Martínez JL; Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, E-28049 Madrid, Spain., Popescu C; CELLS-ALBA Synchrotron, E-08290 Cerdanyola del Valles, Barcelona, Spain., Alonso JA; Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, E-28049 Madrid, Spain. |
| Abstrakt: |
Skutterudite-type compounds based on □Co 4 Sb 12 pnictide are promising for thermoelectric application due to their good Seebeck values and high carrier mobility. Filling the 8 a voids (in the cubic space group Im 3̅) with different elements (alkali, alkali earth, and rare earth) helps to reduce the thermal conductivity and thus increases the thermoelectric performance. A systematic characterization by synchrotron X-ray powder diffraction of different M-filled Co 4 Sb 12 (M = K, Sr, La, Ce, and Yb) skutterudites was carried out under high pressure in the range ∼0-12 GPa. The isothermal equations of state (EOS) were obtained in this pressure range and the Bulk moduli ( B 0 ) were calculated for all the filled skutterudites, yielding unexpected results. A lattice expansion due to the filler elements fails in the description of the Bulk moduli. Topochemical studies of the filler site environment exhibited a slight disturbance and an increased ionic character when the filler is incorporated. The mechanical properties by means of Bulk moduli resulted in being sensitive to the presence of filler atoms inside the skutterudite voids, being affected by the covalent/ionic exchange of the Co-Sb and Sb-Sb bonds. |
