Polarized Raman Spectra of Cesium Nitrate in Solid and Molten States: The Nature of the Disordered Phases

The polarized Raman spectra of the room temperature (ordered) phase and the high temperature (disordered) phase of cesium nitrate have been recorded. The assignment of the spectral bands differs somewhat from earlier reports of the room temperature phase with a to/lo splitting of the ν3(E) band at ∼ 1350–1400 cm−1 reported. In the disordered crystal phase the discrete lattice spectrum is replaced by a broad band at ∼ 90 cm−1 superimposed on an anisotropic wing. However, it is found that the internal vibrational phonons retain their site group and polarization characteristics in the disordered solid. The spectrum obtained for the melt is very similar to that for the disordered crystal at elevated temperature (excepting polarization properties).