Antimony telluride doped with small concentrations of vanadium was recently identified as a diluted magnetic semiconductor. We present a study of the heat transport in single crystals of ${\mathrm{Sb}}_{2-x}{\mathrm{V}}_x{\mathrm{Te}}_3$ with $x=0,$ 0.01, 0.02, and 0.03. Thermopower and thermal conductivity were measured from 1.5 K to 300 K. The thermopower is positive for all samples investigated and has a modest dependence on vanadium content. At low temperatures, the lattice thermal conductivity has an approximate $T^2$ dependence and the data up to 100 K can be fitted well assuming that phonons scatter on boundaries, point defects, charge carriers, and other phonons. Theoretical analysis reveals that the over-riding effect of vanadium impurity is the formation of point defects that suppress heat transport via both mass and elastic strain fluctuations.

• Received 12 April 2002

DOI:https://doi.org/10.1103/PhysRevB.66.125206