Temperature Dependence of the Electrical Properties of Bismuth-Antimony Alloys

Abstract

The electrical resistivity $\ensuremath{\rho}$ and Hall effect $R$ of zone-levelled single crystals of Bi-Sb alloys have been measured in the temperature range from 4.2\ifmmode^\circ\else\textdegree\fi{}K to 300\ifmmode^\circ\else\textdegree\fi{}K. $\mathrm{Log}(\frac{\ensuremath{\rho}}{{\ensuremath{\rho}}_{300}})$ vs $\frac{1}{T}$ curves suggest thermal activation of carriers in the concentration range from 5% to 40% Sb in the temperature range from 25\ifmmode^\circ\else\textdegree\fi{}K to 100\ifmmode^\circ\else\textdegree\fi{}K; approximate activation energies have been inferred from their slopes. The activation energy appears to have a maximum at a concentration near 12%. Some anomalies have been observed in the behavior of $\ensuremath{\rho}$ and $R$ on both sides of this concentration at low temperatures. Lattice parameters for these alloys have also been measured for the entire range of solid solubility. Both a maximum and minimum in the $c$-axis lattice parameter vs concentration occur near the concentration at which anomalies appear in transport properties. These phenomena are discussed in terms of a simple band model proposed by Blount and Cohen.