Hydrogen enhances the radiation resistance of amorphous silicon oxycarbides

We use first principles molecular dynamics to investigate unit displacement processes in amorphous silicon oxycarbides (SiOC) and demonstrate that the introduction of hydrogen (H) into these materials enhances their radiation resistance. Our simulations show that 100 eV knock-ons in H-free SiOC redistribute C through the formation of CO and CC bonds. H counteracts this trend by passivating dangling O bonds and preventing C from coming out of solution. This effect arises from the exceptionally high mobility of H, which leads to the saturation of radiation-induced O and C radicals even before the thermal-spike induced by a high-energy knock-on dies down. Our work suggests that fully hydrogenated SiOC is a promising radiation-resistant material for future nuclear energy applications.

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