OPTICAL-ABSORPTION SPECTRA OF LIQUID SULFUR OVER A WIDE ABSORPTION RANGE

The optical absorption coefficient alpha of liquid sulphur has been measured in a wide absorption range from 5.5 x 10(-2) to 2 x 10(5) cm-1 at temperatures from 130 to 450-degrees-C. For measurement in the high-absorption range beyond 105 cm-1, we have developed an optical cell of our own design with a sample thickness of about 3000 angstrom. It was found that the absorption spectra are substantially changed at the polymerization temperature, especially in the high-absorption region; a new absorption band appears at around 3.25 eV and increases with increasing temperature. We discuss the origin of this new absorption band in the high-absorption region together with the details of the spectral changes in the intermediate and low-absorption regions.