Semiconducting Properties of PtSb2

The Hall coefficient, electrical conductivity, Seebeck coefficient, magnetoresistance, piezoresistance, magnetic susceptibility, and the elastic constants of Pt${\mathrm{Sb}}_2$ have been measured over a wide temperature range (78°K to as high as 1200°K for some of the properties). Samples prepared from a melt of Pt${\mathrm{Sb}}_2$ are $p$ type. $N$-type samples have been prepared by addition of Te. A multivalley valence band with general ellipsoidal constant energy surfaces centered on the axes in $k$ space is the simplest model that can be used to interpret both the magnetoresistance and piezoresistance measurements. The best estimates for the band parameters that could be obtained from the present data are $E_g\sim .07$ eV, ${m_v}^{*}=0.7\mathrm{}{m}_0$, and ${m_c}^{*}=0.5\mathrm{}{m}_0$, where ${m_v}^{*}$ and ${m_c}^{*}$ are the density-of-states masses in the valence and the conduction band, respectively.