Raman Spectra and Ionic Interactions in Molten Nitrates

A simple experimental assembly designed for use with a conventional Toronto-type source and capable of use at temperatures up to 700°C is described for the Raman technique. Application to the series of molten inorganic salts Li, Na, K, Cs, Rb, and Ag/NO3, and selected mixtures of these, is reported. The Raman frequencies, relative intensities, depolarization ratios, and vibrational force constants are discussed. A regular variation of the Raman frequencies and force constants which correlates with the change in the polarizing power of the cationic environment is noted. The results are examined in the light of current views on the structure of molten salts.