Temperature dependence of Raman active modes in CuGeO3

Abstract The Raman scattering spectra of CuGeO 3 were studied in a wide temperature range (20–300 K). Significant phonon frequency shifts were observed in the case of the A g modes at 187 and 859 cm −1 , the B 1 g mode at 224 cm −1 and the B 3 g mode at 388 cm −1 . Only the mode at 859 cm −1 softens, while the remaining three modes harden with decreasing temperature. The asymmetry observed in the A g symmetry phonon lines is interpreted as the interference of the phonon modes with the continuum excitations of magnetic origin.