Raman spectra of orthorhombic sulfate single crystals I: K2SO4, Rb2SO4, Cs2SO4 and Tl2SO4

Abstract

In order to confirm the assignment of the Raman active internal modes of K2SO4 and structurally related crystals, the Raman spectra of oriented cyrstals have been recorded. Using the relative integrated intensities of the bands as data, the transferability of the Raman tensors of the free SO 4−− ion to the crystals was investigated with, in general, good agreement between the calculated and measured intensity distribution. A linear dependence between the frequencies of the internal modes of the K2SO4, Rb2SO4 and Cs2SO4 crystals and the electronegativity of the cations could be observed. Also, a brief discussion about the nature of the lattice modes of these crystals is included. Copyright © 1974 John Wiley & Sons, Ltd.