Temperature dependence of the Raman spectrum of UO2

The position of the main spectral features (located at ∼445, ∼575, ∼625, ∼925 and ∼1145 cm−1) in the Raman spectrum of UO2 has been examined from room temperature up to 600 °C. The wavenumber shifts measured for the observed bands have allowed us to obtain the temperature dependence (dω/dT) of the different vibrational modes. Our measurements corroborate the assignment of the band observed at ∼1145 cm−1 to the 2LO overtone. In addition, the temperature dependence of the bandwidths of the T2g and 2LO modes has been analysed.