RAMAN-SCATTERING IN DIAMOND UP TO 1900-K

The temperature dependence of the zone-center optical phonon of diamond has been investigated up to 1900 K using Raman scattering. Our frequencies agree well with the first measurements of the temperature dependence of this mode but are found to fall halfway between those obtained in two later determinations up to 1000 K. Up to approximately 1000 K, there is a noticeable nonlinearity in the frequency changes; above approximately 1000 K the frequency change is almost linear with temperature. The measured positions and widths are also compared with theoretical calculations.