High pressure Raman study of solid CS2

Abstract

Solid molecular CS2 is investigated in a diamond anvil cell in the temperature and pressure range of 6–300 K and 0–20 GPa, respectively, by means of Raman spectroscopy. The pressure dependence of external and internal vibrational frequencies is determined, and used to draw conclusions about the p–T phase diagram. A very strong influence of sample preparation conditions on the crystal quality, especially at low temperatures, is noticed. It turned out that the librational Raman spectrum provides a sensitive test with respect to the crystalline or amorphous structure of the solids under investigation. In addition the origin of the ν2 fundamental and phonon sidebands, some-times observed in spectra of amorphous CS2, will be discussed. Finally the influence of temperature and pressure is shown in the so-called ‘‘black’’ CS2, a polymerized modification of CS2, which is formed at pressures above 10 GPa.