Band Inversion and the Electrical Properties ofPbxSn1−xTe

The electrical resistivity and Hall coefficient of ${\mathrm{Pb}}_x{\mathrm{Sn}}_{1-x}\mathrm{Te}$ alloys were determined as a function of temperature from 4 to 300°K. The measurements were intended as a test of Dimmock, Melngailis, and Strauss's band-inversion model in the immediate region of band crossing. The resistivity is characterized by a predominantly linear dependence upon $T$, and by the distinct breaks which occur in this dependence. The linearity is attributed to degenerate lattice scattering. The temperatures at which the breaks occur depend upon alloy composition, and are relatively independent of carrier concentration and carrier mobility. These break temperatures are in excellent agreement with band-crossing temperatures predicted on the basis of the band-inversion model. This fact, along with several other features of the results, strongly supports the band-inversion model.