Low-frequency vibrational excitations in the amorphous and crystalline states of triphenyl phosphite: A neutron and Raman scattering investigation

Abstract

The vibrational density of states in the triphenyl phosphite, measured by inelastic neutron scattering, were obtained during isothermal aging at ${T}_{a}=210,$ 213, and 216 K. The low-frequency ${\ensuremath{\omega}}^{n}$ behavior of the vibrational density of states was observed to be time dependent. This is suggestive of an abortive crystallization process because the \ensuremath{\omega} exponent has not reached the characteristic value of the crystalline state $(n=2)$ at the end of the transformation. The confrontation of inelastic neutron scattering and Raman data in the low-frequency range reveals interesting information about the structural organization in the liquid, the glass, the undercooled liquid, and the glacial state, through the observation of the boson peak.