The recycling waste heat from industrial refineries or use of auto exhaust heat to recharge electric car batteries may someday operate far more efficiently thanks to a new alloy developed at Ames Laboratory, USA. A team led by Evgenii Levin has achieved a 25 % improvement in the performance of the thermoelectric material, TAGS. TAGS is composed of tellurium, antimony, germanium and silver, hence the acronym, and converts heat into electrical energy, albeit at low efficiency.
Levin’s team has found that adding 1 % of the rare-earth elements cerium or ytterbium to a TAGS material significantly enhances its performance. Solid-state NMR spectroscopy showed slight broadening in 125Te NMR, attributed to paramagnetic effects. This suggested that Ce and Yb atoms were incorporated into the lattice, leading to possible formation of resonance states near the Fermi level or carrier scattering by lattice distortions and/or by paramagnetic ions, both of which could explain the enhanced performance.
- Analysis of Ce- and Yb-Doped TAGS-85 Materials with Enhanced Thermoelectric Figure of Merit
E. M. Levin, B. A. Cook, J. L. Harringa, S. L. Bud’ko, R. Venkatasubramanian, K. Schmidt-Rohr,
Adv. Funct. Mater. 2011, 21(3), 441–447.