Journal of Electronic Materials

, Volume 42, Issue 7, pp 1622–1627

Lower Thermal Conductivity and Higher Thermoelectric Performance of Fe-Substituted and Ce, Yb Double-Filled p-Type Skutterudites

  • Sedat Ballikaya
  • Neslihan Uzar
  • Saffettin Yildirim
  • Hang Chi
  • Xianli Su
  • Gangjian Tan
  • Xinfeng Tang
  • Ctirad Uher
Article

DOI: 10.1007/s11664-012-2357-2

Cite this article as:
Ballikaya, S., Uzar, N., Yildirim, S. et al. Journal of Elec Materi (2013) 42: 1622. doi:10.1007/s11664-012-2357-2

Abstract

Substituting Fe on Co sites is an effective way to produce p-type skutterudite compounds as well as to reduce the thermal conductivity of skutterudites. In this work, we investigated thermoelectric properties of Fe-substituted and Ce + Yb double-filled CexYbyFezCo4−zSb12 (x = y = 0.5, z = 2.0 to 3.25 nominal) skutterudite compounds by studying the Seebeck coefficient, electrical conductivity, thermal conductivity, and Hall coefficient over a broad range of temperatures. All samples were prepared by using the traditional method of melting–annealing and spark plasma sintering. The signs of the Hall coefficient and Seebeck coefficient indicate that all samples are p-type conductors. Electrical conductivity increases with increasing Fe content. The temperature dependence of electrical conductivity indicates that a transition from the extrinsic to the intrinsic regime of conduction depends on the amount of Fe substituted for Co. The temperature dependence of mobility reflects the dominance of acoustic phonon scattering at temperatures above ambient. Except for Ce0.5Yb0.5Fe3.25Co0.75Sb12, the thermal conductivity increases with increasing Fe content, reaching the maximum value of 2.23 W/m K at room temperature for Ce0.5Yb0.5Fe3CoSb12. A high power factor (27 μW/K2 cm) combined with a rather low thermal conductivity for Ce0.5Yb0.5Fe3.25Co0.75Sb12 (nominal) lead to a dimensionless figure of merit ZT = 1.0 at 750 K for this compound, one of the highest ZT values achieved in p-type skutterudite compounds prepared by the traditional method of melting–annealing and spark plasma sintering.

Keywords

Thermoelectric properties p-type skutterudites Ce, Yb double filled thermal conductivity Seebeck coefficient 

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Copyright information

© TMS 2012

Authors and Affiliations

  • Sedat Ballikaya
    • 1
    • 2
  • Neslihan Uzar
    • 1
  • Saffettin Yildirim
    • 1
  • Hang Chi
    • 2
  • Xianli Su
    • 3
  • Gangjian Tan
    • 3
  • Xinfeng Tang
    • 3
  • Ctirad Uher
    • 2
  1. 1.Department of PhysicsUniversity of IstanbulIstanbulTurkey
  2. 2.Department of PhysicsUniversity of MichiganAnn ArborUSA
  3. 3.State Key Laboratory of Advanced Technology for Materials Synthesis and ProcessingWuhan University of TechnologyWuhanChina

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