Thermal Conductivity of Diamond Between 170 and 1200 K and the Isotope Effect
The thermal conductivity of single-crystal diamond has recently received increased attention resulting from an announcement by General Electric of a 50% enhancement in the thermal conductivity of synthetic diamond of high isotopic purity at room temperature. This increase was unexpected by standard theory. Thermal conductivity measurements on natural diamond between 500 and 1200K, and on synthetic, nearly isotopically pure (0.07% 13 C) diamond between 170 and 320K are reported here. The large temperature range allows a more accurate determination of the isotope effect than previously possible[1,2].