THALLIUM COMPOUND THERMOELECTRIC CONVERSION MATERIAL AND PRODUCTION METHOD THEREFOR

摘要

A material exhibiting a good thermoelectric conversion performance, that is, a material exhibiting a thermoelectric conversion non-dimensional performance index ZT exceeding 1. It has been found that a composite intermetallic compound having a specific composition and containing Ag, Tl and Te as component elements has a high Seebeck coefficient and a low electric resistivity, has an extremely low heat conductivity, and is useful for a thermoelectric conversion material in a thermoelectric conversion element. In particular, an Ag-Tl-Te ternary system compound having a composition in the vicinity of Ag<SUB>9</SUB> TlTe<SUB>5</SUB> is excellent as a thermoelectric conversion material, and its non-dimensional performance index ZT far exceeds 1, with the maximum value of ZT at 700K being 1.42. It is used as a p-type thermoelectric conversion material. To produce it, just mix Ag<SUB>2</SUB>Te<SUB>0.5-1.5</SUB> and Tl<SUB>2</SUB>Te<SUB>0.5-1.5</SUB> at a ratio of 9:1, and then melt and cool the mixture.