The correlation between the thermoelectric properties and stoichiometry in the boron carbide phase B4C-B10.5C

Electrical conductivity, thermoelectrical power and thermal conductivity measurements on boron carbide samples show that the electrical conductivity follows the small polaron hopping theory and that thermal conductivity occurs by phonon diffusion. The evolution of these properties with carbon content illustrates the particular role played by the 13.3 at% C compound in the phase homogeneity range B_10.5C to B₄C. The value of the figure of merit (0.85×10^–3 K at 1250 K) proves that this particular boron carbide compound could be a very interesting candidate material for high-temperature thermoelectrical conversion.