Low-frequency Raman scattering in As₂S₃glass former around the liquid–glass transition

Low-frequency light scattering spectra of As 2 S 3 glass former have been investigated over a temperature range of 300–712 K. Using the model of a damped oscillator, the parameters of the intensities of the boson peak and of the fast relaxation as well as the boson peak position and the relaxational time are extracted as a function of temperature. The temperature increase of the fast relaxation becomes more sharp above T g and stabilizes at T = 600 K. By analogy with other glass formers it is suggested that the critical temperature T c within the framework of the mode-coupling theory should be near 600 K for As 2 S 3 . It was found that the damping parameter at T c is the same for As 2 S 3 and B 2 O 3 ; an explanation of this coincidence is suggested. The boson peak is found to be present up to 712 K with almost the same strength as at low temperatures.