Skutterudites: A new class of promising thermoelectric materials
- Jet Propulsion Laboratory/California Institute of Technology 4800, Oak Grove Drive, MS 277-212, Pasadena, California 91109 (United States)
Based on literature data and experimental findings at the Jet Propulsion Laboratory (JPL), semiconductors with the skutterudite structure TPn{sub 3} (where T is a transition metal element such as Co, Rh, Ir, Ni, and Pd, and Pn is a pnicogen element such as P, As, and Sb) possess attractive characteristics and show a good potential for high {ital ZT} values. The high degree of covalency results in high mobility and low electrical resistivity values while a relatively complex 32 atom unit cell results in a reasonably low thermal conductivity. Both {ital n}-type and {ital p}-type electrical conductivity samples have been obtained. Room temperature Seebeck coefficient values up to 200 {mu}VK{sup {minus}1} for {ital p}-type and up to {minus}600 {mu}VK{sup {minus}1} for {ital n}-type have also been measured on several of these materials. In addition, the large number of isostructural compounds, solid solutions and related phases offer many possibilities for optimization of the transport properties to a specific temperature range of thermoelectric applications. By replacing the transition metal or the pnicogen atom by two of its neighboring elements and ensuring that the number of valence electrons is retained, many ternary phases can be successfully derived from the original CoAs{sub 3} skutterudite structure. Some of these materials were found to have substantially lower thermal conductivities compared to those of the binary compounds. The composition, band gap and doping level can be tailored to achieve maximum performance. An overview of the results obtained to date is provided and our approach to achieving high {ital ZT} materials are discussed in this paper. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 172164
- Report Number(s):
- CONF-940830-; ISSN 0094-243X; TRN: 96:003253
- Journal Information:
- AIP Conference Proceedings, Vol. 316, Issue 1; Conference: 13. international conference on thermoelectrics, Kansas City, MO (United States), 30 Aug - 1 Sep 1994; Other Information: PBD: 10 Aug 1994
- Country of Publication:
- United States
- Language:
- English
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