A reader has brought to my attention the following remarkable paper:
A. Bentien, S. Johnsen, G. K. H. Madsen, B. B. Iversen, and F. Steglich, "Colossal Seebeck coefficient in strongly correlated semiconductor FeSb2," Europhysics Letters (EPL), pp. 17008, 2007.
Aparently due to strong corellation and d- character of the bands, FeSb2 exhibits at 12 K perhaps the largest electrical power factor ever reported:
"S2/rho = 2300 µW/K-cm2 at 12 K and is 65 times larger than the value for state-of-the-art Bi2Te3-type thermoelectric materials."
The lattice thermal conductivity is still quite large so ZT ~ 0.005 at 12 K, but with a Seebeck of -45,000 µV/K the material is bound to be of interest.
Off hand I’m not aware of any other example of such large Seebeck values in anything which might be remotely described as a decent electrical conductor.
The full manuscricpt can be downloaded for free from the journal’s website using this link: