Monitoring of the microstructure of ion-irradiated nuclear ceramics by in situ Raman spectroscopy
Résumé
Raman spectroscopy is an efficient technique for studying the evolution of microstructure of materials under irradiation. For that purpose, a Raman spectrometer has been recently installed at the JANNUS-Saclay platform. In this paper, we describe the new setup for in situ experiments. These in situ experiments allowed following the microstructural evolution of different materials (SiC, ZrO2 and B4C) as a function of ion fluence on a single sample (either single crystal or polycrystalline ceramics) under the same irradiation conditions. Our results show that Raman spectroscopy is a versatile non-contact technique for studying on-line crystalline phase changes or amorphization of irradiated iono-covalent solids. A detailed analysis of Raman spectra is provided for the three materials (SiC, ZrO2 and B4C) investigated in this study, revealing quite different behaviors upon irradiation. Basically, Raman spectroscopy gives insight on these evolutions at the level of bonds given by specific phonon modes, in good agreement with Rutherford backscattering channeling (RBS/C), X-ray diffraction (XRD) or transmission electron microscopy (TEM) data, which provide information at a long-range scale. Copyright (c) 2015 John Wiley & Sons, Ltd.