Conduction mechanism in boron carbide

Electrical conductivity, Seebeck-coefficient, and Hall-effect measurements have been made on single-phase boron carbides, ${\mathrm{B}}_{1\ensuremath{-}x}{\mathrm{C}}_{x}$, in the compositional range $0.1\ensuremath{\le}x\ensuremath{\le}0.2$ 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.