INFLUENCE OF POINT-DEFECTS ON THE THERMAL-CONDUCTIVITY OF DIAMOND SINGLE-CRYSTALS - STATE-OF-THE-ART

A new mechanism for the scattering of heat-carrying phonons has been s uggested, based on the assumption of the activation of normal processe s by isotopes. An attempt is made to explain the high response of the thermal conductivity of diamond single crystals to isotopic impurity c oncentration. On the basis of the mechanism suggested, the concentrati on and temperature dependences of the thermal conductivity of diamond have been calculated and compared with the experimental data available . For synthetic industrial diamond made by spontaneous crystallization , the effects of nitrogen impurities and vacancies on thermal conducti vity have been estimated. An assumption has been made that nitrogen an d vacancy defects are generated as structural elements in the process of diamond synthesis.