THERMAL-CONDUCTIVITY AND SPECIFIC-HEAT OF BORON CARBIDES

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