Density of vibrational states and light-scattering coupling coefficient in the structural glassand glassy crystal of ethanol

Abstract

The density of vibrational states in the terahertz regime of ethanol in both the structuralglass and the glassy crystal has been extracted from low-temperature specific heat datapublished previously via the Tikhonov regulation method. In addition, low-frequencylight-scattering (LS) spectra (boson peak) have been measured for these two phases at lowtemperature (11 K) applying a tandem Fabry–Pérot interferometer. By comparingthe LS data and the density of states, the light-vibration coupling coefficient isextracted. It is shown that the coupling coefficient is essentially the same forboth disordered phases, obeying a linear frequency dependence down to 200 GHz.