Theoretical analysis of the thermal conductivity of diamond in a two-step model

The recent measurements of thermal conductivity of diamond are explained by the two-step model of normal process. The phonon scattering of isotopic defects is used as a main variable to fit the measurements. The enhancement of thermal conductivity at 300 K by reduction of the isotope concentration from 1.1% to 0.07% is as high as 16%. We also attempt to compare with other recent theoretical works which were calculated in the Callaway model.