Low frequency Raman scattering from aqueous sucrose solution

Low frequency Raman spectra of aqueous sucrose solution with percent sucrose concentration c = 85 have been recorded as a function of temperature in the range 200-353 K. The line shape of the spectrum has been analysed using a model by Gochiyaev, Malinovski, Novikov and Sokolov (GMNS). Boson peak frequency omega (m) is found to decrease with increasing temperature from similar to 46 cm(-1) at 200 K to similar to 28 cm(-1) at 353 K. Spectral intensity and relaxation time change discontinuously at T-1 = 313 K. No discontinuity is observed near the bulk transition temperature T-g = 265 K measured by differential scanning calorimetry (DSC). Renormalised boson peak frequency omega (0) approaches zero at T-2 similar to 363 K which, according to the GMNS model, is the temperature at which vibrational modes soften. There appears to be another inelastic peak around 12 cm(-1). Presence of two inelastic peaks has not been observed before. (C) 2001 Elsevier Science B.V. All rights reserved.