The boson peak in Raman spectra of AsxS1−x glasses

This is the authors' abstract. We don't add key points for this paper.

The Raman spectra of As x S 1− x glasses with x < 40 at % ( Z < 2.4) have been studied in a wide temperature range (20–300 K). A well resolved boson peak is observed in the low-frequency portion of the spectrum, not withstanding the appearance of floppy modes in the glasses under study. It is shown that the boson peak is characterized by two parameters: intensity and the peak position. A comparison of the intensity variation for the boson peaks indicates that the degree of disorder increases as x decreases. This effect is caused by floppy modes in the glass network and by sulfur phase separation. Studies of reduced boson peaks in the Raman spectra of As x S 1− x glasses confirms the theoretical assumption that the shape of the peaks is independent of composition and temperature.