Unchanged thermopower enhancement at the semiconductor-metal transition in correlated FeSb${}_{2-x}$Te${}_x$

Abstract

Substitution of Sb in FeSb${}_2$ by less than 0.5% of Te induces a transition from a correlated semiconductor to an unconventional metal with large effective charge carrier mass $m^{\ast }$. Spanning the entire range of the semiconductor-metal crossover, we observed an almost constant enhancement of the measured thermopower compared to that estimated by the classical theory of electron diffusion. Using the latter for a quantitative description one has to employ an enhancement factor of 10-30. Our observations point to the importance of electron-electron correlations in the thermal transport of FeSb${}_2$, and suggest a route to design thermoelectric materials for cryogenic applications.

arXiv comment3 pages, 3 figures, accepted for publication in Appl. Phys. Lett. (2011)

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• Kondo Insulator description of spin state transition in FeSb2
• Thermopower of correlated semiconductors : application to FeAs2 and FeSb2
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Cited by in corpus (5)

• Thermoelectricity in correlated narrow-gap semiconductors
• Highly Dispersive Electron Relaxation and Colossal Thermoelectricity in the Correlated Semiconductor FeSb${}_2$
• Enhancement of the thermoelectric properties in doped FeSb${}_2$ bulk crystals
• Metallic surface states in a correlated d-electron topological Kondo insulator candidate FeSb2
• Enhanced electron correlations in FeSb${}_2$