Volume swelling of amorphous SiC during ion-beam irradiation

Relationships between chemical short-range order and volume swelling of amorphous silicon carbide (SiC) under radiation environments have been examined using energy-filtering transmission electron microscopy in combination with imaging plate techniques. Single crystals of $4\mathrm{H}\mathrm{Si}\mathrm{C}$ with (0001) orientation were irradiated with $300\phantom{\rule{0.3em}{0ex}}\mathrm{keV}$ xenon ions to a fluence of ${10}^{15}\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}2}$ at cryogenic $(120\phantom{\rule{0.3em}{0ex}}\mathrm{K})$ and elevated $(373\phantom{\rule{0.3em}{0ex}}\mathrm{K})$ temperatures. A continuous amorphous layer was formed in both specimens, but the magnitude of their volume change was different: volume swelling becomes more pronounced with decreasing irradiation temperatures. From radial distribution function analyses, it was found that the amount of $\mathrm{Si}\mathrm{Si}$ atomic pairs increases more rapidly than that of $\mathrm{C}\mathrm{C}$ atomic pairs with the progress of chemical disordering. We discuss the ion-beam-induced swelling in amorphous SiC within the context of our results as well as previous observations.