Accession Number : AD0274717

Title :   EFFECTS OF VARIOUS IMPURITIES ON LATTICE THERMAL CONDUCTIVITY IN BISMUTH TELLURIDE

Corporate Author : BATTELLE MEMORIAL INST COLUMBUS OHIO

Personal Author(s) : BEER,A.C. ; BATE,R.T.

Report Date : 30 APR 1962

Pagination or Media Count : 1

Abstract : An investigation was made of the effects of lattice imperfections, with particular emphasis on alloying, on the lattice thermal conductivity, K sub L, of thermoelectric materials such as Bi2Te3 or PbTe. It was found that these imperfections can cause a significant reduction in K sub L at room temperatures, and that in the vicinity of liquid nitrogen temperatures the effect can be quite pronounced. Another noticeable factor at temperatures below 200 K is the deviation in temperature dependence from a 1/T behavior, with K sub L becoming essentially temperature independent or exhibiting anomalous maxima in the vicinity of 80 K. Except for the cases involving the anomalies, it was possible to account for the effect of the alloying by taking into account the scattering of lattice waves by (1) elastic strain fields around the static imperfections, because of anharmonicity in the interatomic forces, (2) disturbances resulting from a foreign atom being bound to its neighbors by binding forces of different elastic properties from those of the normal interatomic forces in the host crystal, and (3) perturbations arising from the substitutional atom having a different mass. (Author)

Descriptors :   *BISMUTH COMPOUNDS, *TELLURIDES, *THERMAL CONDUCTIVITY, BISMUTH ALLOYS, CRYSTAL LATTICES, IMPURITIES, INTERMETALLIC COMPOUNDS, SELENIDES, SELENIUM ALLOYS, SEMICONDUCTORS, TELLURIUM ALLOYS, TEMPERATURE, THERMOELECTRICITY

Distribution Statement : APPROVED FOR PUBLIC RELEASE