Effect of Xe ion (167 MeV) irradiation on polycrystalline SiC implanted with Kr and Xe at room temperature

Abstract

The effect of swift heavy ion (Xe 167 MeV) irradiation on polycrystalline SiC individually implanted with 360 keV Kr and Xe ions at room temperature to fluences of 2×10 16 cm -2 and 1×10 16 cm -2 respectively, was investigated using transmission electron microscopy (TEM), Raman spectroscopy and Rutherford backscattering spectrometry (RBS). Implanted specimens were each irradiated with 167 MeV Xe +26 ions to a fluence of 8.3×10 14 cm -2 at room temperature. It was observed that implantation of 360 keV Kr and Xe ions individually at room temperature amorphized the SiC from the surface up to a depth of 186 and 219 nm respectively. Swift heavy ion (SHI) irradiation reduced the amorphous layer by about 27 nm and 30 nm for the Kr and Xe samples respectively. Interestingly, the reduction in the amorphous layer was accompanied by the appearance of randomly oriented nanocrystals in the former amorphous layers after SHI irradiation in both samples. Previously, no similar nanocrystals were observed after SHI irradiations at electron stopping powers of 33 keV/nm and 20 keV/nm to fluences below 10 14 cm -2 . Therefore, our results suggest a fluence 2 threshold for the formation of nanocrystals in the initial amorphous SiC after SHI irradiation.Raman results also indicated some annealing of radiation damage after swift heavy ion irradiation and the subsequent formation of small SiC crystals in the amorphous layers. No diffusion of implanted Kr and Xe was observed after swift heavy ion irradiation.

Effects of swift heavy ion irradiation and annealing on the microstructure and recrystallizationof SiC pre-implanted with Sr ions

“…Irradiation of the implanted SiC with Xe (167 MeV) ions at room temperature to fluences of 3.4 × 10 14 and 8.4 × 10 14 cm −2 caused the partial reappearance of the broad Si-C characteristic Raman peaks at around 775 and 900 cm −1 with the C-C (around 1,425 cm −1 ) and Si-Si (around 525 cm −1 ) peaks still present (see Figure 3). The appearance of the SiC characteristic peaks albeit broad indicates some limited recrystallization of the initially amorphous SiClayer.Similar recrystallization of SiC predamaged by different implanted ions after SHIs irradiation has been reported previously (Debelle et al, 2012;Hlatshwayo et al, 2015;Hlatshwayo et al, 2016;Abdelbagi et al, 2019b;Abdelbagi et al, 2022). In our previous studies, transmission electron microscopy (TEM) and Raman spectroscopy were used to study the structural changes of the as-implanted SiC after SHIs irradiation (Hlatshwayo et al, 2015;Hlatshwayo et al, 2016;Abdelbagi et al, 2019b;Abdelbagi et al, 2022).…”

“…It has been reported in the previous studies that the irradiation of SiC with ions of energies E< 0.5 MeV amorphized SiC depending on the irradiation fluence, temperature and ion mass (Wendler et al, 1998;Weber et al, 2001;Debelle et al, 2010;Abdelbagi et al, 2019a;Abdelbagi et al, 2019b). However, the recrystallization of an initially damaged/amorphous layer of polycrystalline SiC was observed after irradiation by SHIs at room temperature and 500 °C (Hlatshwayo et al, 2015;Hlatshwayo et al, 2016;Abdelbagi et al, 2019a;Abdelbagi et al, 2019b). This was due to the SHIs(with energy >5 MeV) transferring their energy into the target electrons in the bombardment process which cause thermal spikes depending on the energy transferred, i.e., electronic stopping power (Debelle et al, 2012).…”

“…Several studies have been done on the recrystallization of amorphous SiC after irradiation by SHIs (Debelle et al, 2012;Hlatshwayo et al, 2015;Hlatshwayo et al, 2016;Abdelbagi et al, 2019a;Abdelbagi et al, 2019b). However, not many investigations have been conducted on the recrystallization (as well as the microstructure) of the SHIs irradiated SiC after annealing at elevated temperatures.…”

In situ TEM investigations of the microstructural changes and radiation tolerance in SiC nanowhiskers irradiated with He ions at high temperatures

“…A crucial approach for designing radiation resistant materials is to promote an efficient recovery of irradiation-induced defects as soon as they form [19], [20]. Recent studies have shown that tailoring the grain size of SiC by making it nanocrystalline (grain sizes <100 nm) introduces a high number of defect sinks [21], [22] greatly improving its radiation tolerance.…”

Mono-Versus Poly-Crystalline SiC for Nuclear Applications

“…It is thus essential to study SiC behavior under irradiation of such heavy element especially in terms of Xe retention, amorphization and material swelling. Few studies have examined the behavior of Xe in SiC [6][7][8][9][10] but the effect of SiC crystalline microstructure on such irradiation behavior is not completely understood, especially at high fluence. This is the main target of the present work.…”