Raman spectrum of U4O9: a new interpretation of damage lines in UO2

Characterisation of uranium oxides in different conditions is a challenge both in nuclear and environment sciences. We focus here on U4O9, which is a superstructure of UO2. Homogeneous U4O9 powder was fabricated and characterised by Raman spectroscopy. The Raman spectrum of a pure-phase U4O9 is, for the first time, completely described and interpreted. U4O9 Raman spectrum derives from the well characterised one of UO2. Besides reminiscent modes of UO2, a band at 630 cm(-1), which has a specific response to polarised light, was interpreted as characteristic of clusters of interstitial oxygen atoms. These experimental data will help to rationalise the interpretation of UO2 damaged samples. Copyright (C) 2011 John Wiley & Sons, Ltd.