TEMPERATURE-DEPENDENCE OF 1ST-ORDER RAMAN-SCATTERING IN CUGAS2

We have measured the temperature dependence of the first-order Raman scattering Of CUGaS2 single crystals in the range 10-300 K. The frequency shift analysis shows that the purely anharmonic contribution to the shift is a constant, within experimental error, in the range 100-295 K. The values of (domega/dT)upsilon are inversely related to the values of the mode Gruneisen parameter. We show that the model assuming decay of the Raman phonons into two acoustical phonons belonging to the same branch, first proposed by Klemens's, does not adequately represent the temperature dependence of the Raman line width.