1206.4428 (M. X. Chen et al.)

Optimizing thermoelectric properties of filled MPt$_4$Ge$_{12-x}$Sb$_x$
skutterudites by band engineering    [PDF]

M. X. Chen, R. Podloucky, S. Humer, E. Bauer an P. Rogl

On the basis of density functional theory (DFT) calculations thermoelectric properties are derived for Sb-doped skutterudites MPt$_4$Ge$_{12-x}$Sb$_x$ with M=Ba,La,Th. It is predicted that the originally very small size of Seebeck coefficients $S$ of the undoped compounds is increased by factors of 10 or more for suitable dopings. The optimal dopings correspond to a "magic" valence electron number for which all electronic states up to a (pseudo)gap are filled. The theoretical findings are corroborated by measurements of $S$ for LaPt$_4$Ge$_{12-x}$Sb$_x$ skutterudites. DFT derived vibrational rattling-like modes for LaPt$_4$Ge$_{12}$ indicate a small value for the lattice thermal conductivity which in combination with a large value of $S^2$ makes the La-based skutterudites appear as promising thermoelectric materials.

View original: http://arxiv.org/abs/1206.4428