Simulation of defect evolution in irradiated materials: Role of intracascade clustering and correlated recombination

Modeling of long-term defect evolution in heavy-ion irradiated 3C-SiC: Mechanism for thermal annealing and influences of spatial correlation

“…5(b), leaving more mobile interstitials for recombination. The difference in the annealing behaviors of cascade damage and isolated point defects of SiC is much less significant than that of Fe, 23 where most of the defects have been annealed by 500K for isolated defects, but the annealing of cascade damage was insignificant up to that temperature. The less significant difference in SiC compared to iron can be attributed to the fact that SiC cascades possess dispersed structures with low density multiple branches, 18,19 while the Fe cascades have compact spherical structures with vacancy-rich cores surrounded by interstitial-rich regions, 18,75 much more different from uniformly distributed point defects.…”

“…Considering that the decreasing tendency of dissociation barriers with the increase of cluster sizes indicated by H. Jiang et al, 64 the larger clusters in cascade damage are more inclined to dissociate, as it is the case of Fe where additional recovery peaks related to the dissociation of large clusters can be found in the annealing of cascade damage. 23 In addition, the number density of vacancy cluster is much lower, and the annealing of antisite pair defects is absent in the case of isolated point defects. Such effects can be mitigated by introducing defect clusters and antisite pairs randomly in the case of isolated defects.…”

“…23 The lower end of temperature at Stage I corresponds to the onset of C I migration, which only depends on the migration barriers and does not change with dose. However, the width of the recovery peak shrinks with increase in dose.…”

“…KMC has been extensively applied to simulate the long-term evolution of radiation damage in metals. [21][22][23][24][25][26][27] However, KMC simulation for defect recovery in SiC is limited. Using kinetic lattice Monte Carlo (KLMC) and based on parameters from MD simulation, Rong et al has studied the defect recovery in 3C-SiC, extended the annealing time of a MD cascade from 10ps to minutes, 27 although only a single cascade was annealed.…”

“…J. Dalla Torre et al 31 have demonstrated that Cluster Dynamics (CD) based on the mean-field approximation cannot reproduce the correlated recombination in the annealing of electron-irradiated iron. Oritz et al 23 have simulated the long-term annealing of isolated Frenkel pairs and cascade damage in iron by object kinetic Monte Carlo (OKMC) and MFRT. The results indicate that compared to annealing of isolated defects, new recovery peaks at high temperature appear in the case of cascade damage annealing.…”