The infrared spectra of matrix isolated uranium oxide species

The infrared spectra of matrix isolated uranium oxides have been studied by several investigators [1-6].1 Although the spectra were similar, these workers differed in their interpretation and assignm.ent of the observed bands. In particular, AbramoWItz et a1. [1, 2]; and Leary et a1. [3]; assigned two absorption bands at 873 and 776 cml to UOz and UO while Carstens et al. [4], and Gabelnick et al. [5, 6], assigned the features at 776 and 820 cmI to U02 and UO respectively. All workers with the exception of Carstens et al. [4] used oxygen isotopically enriched urania to support their assignments. The uranium oxides were prepared by vaporization of the solid oxides from Knudsen effusion cells [1-3, 5, 6]. Carstens et al. prepared uranium oxides by chemically sputtering a uranium metal cathode with an argonoxygen mixture by means of a discharge in a hollow cathode device [4]. By the latter technique , it was possible to monitor the UO/U02/U03 ratio by changing the oxygen/ argon concentration. It has been shown that the reaction of U(g), and oxygen species 0, O2 , and 0 3 yield the ionic species UO + and UOt in addition to the neutral products. Because of the uncertainty inherent in the sputtering technique as to the state of the oxygen species and/or uranium atoms it was felt worthwhile to perform these experiments with well characterized uranium beams obtainable from Knudsen cells. The reaction products were deposited on gold plated OFHC copper discs so that the ionic species that are produced in these reactions will be neutralized. The products of the reaction of an uranium beam with varying dilutions of argon-oxygen and argon-nitrous oxide mixtures were studied. In this way one could in principle produce different relative concentrations of UO,