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Title: Influence of substituting Sn for Sb on the thermoelectric transport properties of CoSb{sub 3}-based skutterudites

Band structure calculations that incorporate impurity effects suggest that a band resonant state may be formed in p-type CoSb{sub 3}-based skutterudites by replacing Sb atoms with Sn dopant atoms. Such resonant states have the potential to greatly improve thermoelectric energy conversion efficiency by increasing the density of states variation near the Fermi level, thereby increasing the Seebeck coefficient at a given carrier concentration. Through transport measurements of the Seebeck coefficient, electrical conductivity, thermal conductivity, and Hall coefficient, we show that a practical band resonant state is not achieved by Sn doping. Compared to undoped CoSb{sub 3}, the dimensionless figure of merit (ZT) in Sn-doped CoSb{sub 3} is enhanced slightly at high temperatures to a value of 0.2, mostly due to a reduction in thermal conductivity. The Fermi level is calculated not to reach the band resonant state induced by Sn impurity atoms within the range of Sn concentrations examined here.
Authors:
 [1] ;  [2] ; ;  [3] ;  [4] ;  [5] ;  [2] ;  [6] ;  [1] ;  [6] ;  [7]
  1. Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)
  2. Department of Mechanical and Aerospace Engineering, Ohio State University, Columbus, Ohio 43210 (United States)
  3. Sandia National Laboratories, Livermore, California 94550 (United States)
  4. AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, 30-059 Krakow (Poland)
  5. Chemical and Materials Systems Laboratory, GM R and D Center, Warren, Michigan 48090 (United States)
  6. (United States)
  7. Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States)
Publication Date:
OSTI Identifier:
22277900
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 10; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANTIMONIDES; ANTIMONY; COBALT COMPOUNDS; COMPARATIVE EVALUATIONS; CONCENTRATION RATIO; DOPED MATERIALS; ELECTRIC CONDUCTIVITY; ELECTRONIC STRUCTURE; ENERGY EFFICIENCY; FERMI LEVEL; HALL EFFECT; SEEBECK EFFECT; THERMAL CONDUCTIVITY; THERMOELECTRIC CONVERSION; THERMOELECTRIC PROPERTIES; TIN