Investigation of swelling induced by heavy ion and neutron irradiation in SiC

In this paper, the single crystal samples of 6H-SiC were irradiated by 4 MeV Kr-ions, with irradiation fluences from 1.0 × 1016 to 5.0 × 1016 cm−2 at room temperature, 300 °C and 500 °C respectively (5.0 × 1016 cm−2 at 550 °C). The irradiation-induced swelling was strictly measured by X-ray Diffraction (XRD) and 3D surface profile. It is shown that the swelling strongly depends on the irradiation temperature and the ion fluence, and the magnitudes of volumetric swelling saturate at approximately 3.3% and 2.4% at the irradiation temperatures of 300 °C and 500 °C, respectively. Those magnitudes are higher than the neutrons' data at the same temperature. Furthermore, this paper exhaustively investigates the differences and similarities between heavy-ion and neutron irradiation-induced swelling; we suppose that the larger saturate swelling is caused by excess substitute vacancies in Si sub-lattice induced by Kr ions. Finally, by systematically analyzing the swelling data, it was speculated that the heavy-ion irradiation needs a higher dose to saturate the swelling compared to neutron at the same irradiation temperatures.