Raman Spectroscopic Investigation of Ucl4

Abstract

Uranium chloride salts are a proposed fuel source for molten salt reactors (MSRs). However, despite their relevance to nuclear energy, they remain understudied, in part because of their air sensitivity. This work provides the first Raman spectra of UCl4 from 45 to 4000 cm−1 collected with 532 and 785 nm excitation sources as well as the assignment of 10 identified peaks to their respective vibrational modes. These Raman bands are compared with those for isostructural ThCl4, the compositionally related UCl3, and the computed Raman bands for UCl4 from local vibrational mode analysis. The observed spectrum of UCl4 in is accord with that of ThCl4 and the computed spectra of UCl4. We posit that the observed differences between the spectra of UCl4 and UCl3 are useful in differentiating these species for applications such as in situ monitoring of MSR operations.

Keywords: Uranium tetrachloride, Raman Spectroscopy, molten salt reactors, anoxic spectroscopy