Year: 2004
Type: article
Abstract: Inelastic x-ray scattering and Brillouin light scattering measurements of the dynamic structure factor of liquid hydrogen fluoride have been performed in the temperature range $T=214--283\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The data, analyzed using a viscoelastic model with a two time-scale memory function, show a positive dispersion of the sound velocity $c(Q)$ between the low frequency value ${c}_{0}(Q)$ and the high frequency value ${c}_{\ensuremath{\infty}\ensuremath{\alpha}}(Q)$. This finding confirms the existence of a structural $(\ensuremath{\alpha})$ relaxation directly related to the dynamical organization of the hydrogen bonds network of the system. The activation energy ${E}_{a}$ of the process has been extracted by the analysis of the temperature behavior of the relaxation time ${\ensuremath{\tau}}_{\ensuremath{\alpha}}(T)$ that follows an Arrhenius law. The obtained value for ${E}_{a}$, when compared with that observed in another hydrogen bond liquid as water, suggests that the main parameter governing the $\ensuremath{\alpha}$-relaxation process is the number of hydrogen bonds per molecule.
Source: Physical Review B
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2004292625