Raman spectroscopic study of the uranyl sulphate mineral zippeite: Low wavenumber and U-O stretching regions

摘要

The uranyl sulphate mineral zippeite was studied by Raman spectroscopy. The phase purity of the sample was initially checked by X-ray powder diffraction and its chemical composition was defined by electron microprobe (wavelength dispersive spectroscopy, WDS) analysis. The Raman spectroscopy research focused on the low wavenumber and uranyl stretching vibration regions. Vibration bands down to 50 cm~(-1) were tentatively assigned. The U-O bond lengths were calculated based on empirical relations. Inferred values are consistent with those obtained from the crystal structure analysis of synthetic zippeite. Number of bands was interpreted on the basis of factor group analysis.