Electrical conductivity, Seebeck-coefficient, and Hall-effect measurements have been made on single-phase boron carbides, ${\mathrm{B}}_{1-x}{\mathrm{C}}_x$, in the compositional range $0.1\le x\le 0.2$ between room temperature and 1273 K. The results indicate that the predominant conduction mechanism is small-polaron hopping between carbon atoms at geometrically inequivalent sites.

• Received 12 September 1983

DOI:https://doi.org/10.1103/PhysRevB.29.4582