Low-energy anomalies of vibrational spectra and medium range order in glasses

The low-frequency Raman spectra of glasses were compared with heat capacity data. The comparison shows that full vibrational density of states g(ω) appears in the Raman spectra and that the so-called boson peak is connected with peculiarities of g(ω), but not with the light to vibrations coupling coefficient. A correlation of the boson peak frequency and the width of first sharp diffraction peak is discussed. This correlation supports the idea that the low-energy vibrational anomalies in glasses are defined by some characteristic length of the vitreous structure.