Temperature dependence of the first-order Raman phonon line of diamond

Micro-Raman scattering from single-crystal diamond was performed over the temperature range 77–873 K. These measurements show that the Raman phonon frequency and the linewidth are temperature dependent, the linewidth and the frequency extrapolated to 0 K are $1.103\pm 0.03{\mathrm{cm}}^{\mathrm{-}1}$ and $1332.7\pm 0.2{\mathrm{cm}}^{\mathrm{-}1},$ respectively. A linear relationship was found to exist between the downshift of the Raman frequency and the linewidth. In contrast to other group IV semiconductors, we show that in diamond the dependence of the phonon linewidth on the temperature is well described by the simple Klemens model which assumes that the zone center phonons decay into two acoustical phonons of opposite momentum but belonging to the same acoustic branch.