Irradiation effects in helium implanted silicon carbide measured by X-ray absorption spectrometry

Silicon carbide (SiC) is investigated as a possible structural material for future nuclear power plants. It is utilized as fibre and/or as matrix in ceramic composite materials. The fibre reinforcement is necessary to provide the required ductility. In this work, the behaviour of pure SiC under irradiation by He implantation is studied. Samples are investigated by means of the extended X-ray absorption fine structure (EXAFS) spectroscopy, performed at the Si K-edge. The Fourier transforms of the EXAFS data indicate a decrease of the Si–Si bond related shells around the absorbing Si. The possible damage features are discussed and the three most probable ones for the irradiation conditions are selected for future modelling work.