Guido Roma¹, Gaëlle Gutierrez¹, Kevin Gillet¹, Dominique Gosset¹; ¹CEA

Raman spectroscopy is a widespread technique to characterize irradiated materials. However, the interpretation of experimental spectra in terms of atomic scale modifications is often far from straightforward. In this paper we combine the first principles simulation of Raman spectra of carbon-rich boron carbide with the experimental results obtained before and after heavy ion irradiation. Relying on an embedding procedure we compute the first order Raman tensor of impurities or intrinsic defects at low concentration. Previous works show that the calculated first order Raman spectrum cannot fully explain the experimental spectra obtained for boron carbide. We insert vacancies, interstitials and other defects and we analyze their influence on the spectral features at various concentrations. By comparison with experimental spectra obtained in different conditions, before and after irradiation, we discuss which of the intrinsic defects could be present in the measured samples, also according to their formation energies.