Thermoelectric properties of Pt-doped beta-FeSi2

The thermoelectric properties of Pt-doped beta -FeSi2(Fe1-xPtxSi2) have bee n characterized by Hall effect measurements at 300 K and by measurements of electrical resistivity, Seebeck coefficient, and thermal conductivity from 300 to 1150 K. Fe1-xPtxSi2 is n type over the measured temperature range. The electron concentration of Fe1-xPtxSi2 at 300 K is about twice the Pt at om concentration at low Pt atom concentration. The solubility limit of Pt i n beta -FeSi2 is estimated to be about 2.0 at. %. The electrical conduction of Fe1-xPtxSi2 can be explained by the small polaron mechanism. The therma l conductivity as well as the Seebeck coefficient of Fe1-xPtxSi2 is strongl y affected by the existence of small polarons. The samples for x=0.03 and 0 .05 show a maximum value of ZT=0.14 at 847 K. (C) 2000 American Institute o f Physics. [S0021-8979(00)02424-5].