Low-temperature transport properties ofp-typeCoSb3

Single crystals of the skutterudite ${\mathrm{CoSb}}_3$ exhibit large hole mobilities (up to 3000 ${\mathrm{cm}}^2$ ${\mathrm{V}}^{\mathrm{-}1}$ ${\mathrm{s}}^{\mathrm{-}1}$ at room temperature), intrinsic lattice thermal conductivity down to 10 K, and pronounced phonon drag effects in the thermoelectric power. The dependence of the mobility and diffusion thermopower on hole density is consistent with recent band-structure calculations, which indicate that ${\mathrm{CoSb}}_3$ possesses a highly nonparabolic valence-band structure.