The far IR spectra of zinc chloride in the crystalline, liquid and glassy states have been determined over a range of temperatures in order to help decide whether the long range disorder characteristic of the glassy state can be distinguished as a source of spectral line broadening comparable with the dynamic effects which lead to short phonon lifetimes in hot (anharmonic) crystals and liquids. Though experimental problems associated with ZnCl2 hygroscopicity caused the frequency range of the study to be restricted to the region above 80 cm-1, sufficient data were acquired to show that, at temperatures above the glass transition temperature Tg, the band broadness in the crystalline phase was essentially the same as in the long range disordered phase. Dipole movement correlation functions obtained by Fourier transformation of the high and low frequency parts of the spectrum can be described as damped cosine waves, the damping constant being greater for the low frequency modes. Ordered and disordered phases have essentially equal damping constants at high temperatures, but it appears that below Tg a separate branch for the amorphous phase can be distinguished.
|Original language||English (US)|
|Number of pages||8|
|Journal||Spectrochimica Acta Part A: Molecular Spectroscopy|
|State||Published - Mar 1974|
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