Boson peak behavior of sodosilicate glasses probed by terahertz time-domain spectroscopy

Disordered solids are characterized by a lack of long-range structural order, which influences their vibrational dynamics. The appearance of an excess of vibrational modes over the Debye level at the terahertz frequencies is called the boson peak (BP). However, the origin of the BP is still an unsolved problem. For detecting and interpreting this behavior, we find that the BP also appears in the spectrum of α(ν)/ν² where α(ν) is the absorption coefficient. In this study, we successfully detect the BP behavior of sodosilcate glasses (xNa₂O●(1-x)SiO₂, x = 0.2, 0.25, and 0.33) by terahertz time-domain spectroscopy. Finally, we observe that the BP frequency shifts to a higher value as the Na₂O concentration increases and the shape of the BP becomes broad and blurry as the temperature increases.