Strong electron correlations in FeSb2

FeSb2 has been recently identified as a new model system for studying many-body renormalizations in a d-electron based narrow gap semiconducting system, strongly resembling FeSi. The electron-electron correlations in FeSb2 manifest themselves in a wide variety of physical properties including electrical and thermal transport, optical conductivity, magnetic susceptibility, specific heat and so on. We review some of the properties that form a set of experimental evidences revealing a significant role of correlation effects in FeSb2. The metallic state derived from slight Te doping in FeSb2, which exhibits a large quasiparticle mass, will also be introduced. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim