AbstractSingle crystal silicon carbide (SiC) has been 2 MeV silicon ion irradiated in various irradiation temperature and ion flux ranges to measure the effect of these parameters on the critical dose for amorphization. The temperature and flux range for which amorphization was observed ranged from 80 to 400 K and 0.066 to 3 × 104 dpa/s, respectively. The critical dose, Dcrit was found by locating the depth of the boundary between partially crystalline and fully amorphous material using dark field TEM from samples prepared in cross section. This depth was compared to the damage profile as calculated using the TRIM-96 code. The temperature dependence of Dcrit is found to agree well with previously reported values, though new evidence suggests a defect species becoming mobile in the 250-300 K range. Also of significance is that Dcrit was dependent on flux at 340 K, ranging from 0.79 displacements per atom at the lowest ion flux to ∼0.6 dpa at the highest flux level. The dose rate dependence of Dcrit, is compared with a chemical rate theory model previously described by the authors. It is seen that the dose rate dependence is substantially weaker than theorized. An extrapolation of the measured dose rate dependence is also compared with recent data on fast neutron amorphized SiC.
Influence of Temperature on Static Fatigue Strength of Silicon Carbide.