Thermal conductivity and specific heat of boron carbides

We present measurements of the thermal conductivity (30 < T < 300 K) and specific heat (80 < T < 300 K) of polycrystalline boron carbides (B1-xCx) for carbon concentrations spanning the single-phase field (0.1 < × < 0.2) and compare our results with studies in other temperature regimes. The thermal conductivity decreases continuously with decreasing x as it evolves from crystalline behavior for carbon-rich specimens to a glass-like conductivity characteristic of amorphous solids. The specific heat of boron carbides is insensitive to the carbon concentration for T > 60 K.