MICROSTRUCTURAL ASPECTS OF THE TEMPORAL EVOLUTION OF THE AGING PROCESS IN THERMOELECTRIC (Pb,Sn,Ge)Te COMPOUNDS

Chakogenides of column IV metals display in general favorable thermoelectric properties. The thermoelectric efficiency can be improved by reducing the thermal conductivity via nano-structuring. The latter can be achieved by taking advantage of the phase separation induced by a spinodal decomposition that takes place in the system. The temporal evolution of the microstructure as a function of aging is of interest because it can be used to control the long term thermoelectric efficiency. Various features of the microstructure are presented and discussed.