Irradiation response of SiOC under simultaneous helium and silicon ion irradiation

SiOC is an amorphous ceramic with superior irradiation stability, making it attractive for applications in high-temperature and high-radiation environments. However, its glassy state stability under the synergistic effects of helium introduction and heavy damage cascades, as expected in a reactor, has not yet been fully assessed. In this study, e-gun evaporated SiOC was simultaneously irradiated using 150 keV helium at a 45-degree incident angle and 1.5 MeV silicon self-ions at a normal incident angle, at room temperature, 300 °C, and 500 °C, respectively. For all irradiation conditions, high-resolution transmission electron microscopy and electron diffraction analysis across different depths of the film did not reveal any crystallization. However, Si-enriched precipitates appeared, with fewer precipitates observed at the highest irradiation temperature. Surface scanning electron microscopy showed periodic patterning on the surface of both room temperature and 300 °C irradiated samples, but not on the 500 °C irradiated sample. The study demonstrates the overall excellent amorphization resistance of SiOC.