Mono-Versus Poly-Crystalline SiC for Nuclear Applications

Abstract

3C-SiC layers of different microstructures (monocrystalline (100) and (111) oriented and polycrystalline) were implanted with high energy (800 keV) 129Xe++ ions. Implantations were performed at room temperature (RT) and at 500 °C using two different fluences of Φ1 = 1x1016 and Φ2 = 1x1017 at/cm2. Surface blistering was only observed for RT and Φ2 implantations into poly-SiC material while mono-SiC kept rather smooth surface. This was due to more homogeneous Xe bubbles distribution (200 nm deep) in the mono-SiC than in the poly-SiC. Xe retention was found to be almost complete for all samples. Some Xe enhanced diffusion was detected in the poly-SiC material which was attributed to grain boundaries. Some irradiation-induced oxidation effect was evidenced, O element being located at the depth where Xe bubbles are accumulating. This was more pronounced for poly than for mono-SiC. These results demonstrate that SiC microstructure affects many aspects of its behavior upon Xe irradiation.