It has long been observed that a crystalline-to-amorphous (c-a) transition occurs in silicon carbide (SiC) irradiated at low temperature. However, the microscopic mechanisms leading to the transition are not well understood. We report in this paper a molecular dynamics (MD) simulation of low-energy (100 eV) recoil accumulation at cryogenic temperature (20 K), up to approximate to 1 dpa, in which the irradiated computational sample becomes amorphous and is subsequently annealed at high temperature (2320 K). The simulation suggests that, at least for low-mass impinging particles, provided that no direct impact amorphization (DIA) takes place, the driving forte for the c-a transition in this material is the accumulation of Frenkel pairs up to a critical concentration (approximate to 1.9 x 10(22) cm(-3)). The role of antisites in the process is negligible. In fact, antisite formation during the annealing could be the bottleneck for complete recovery. A simple and intuitive analytical model based on the concepts of recombination barriers and interstitial migration is also proposed, to describe the temperature dependence of the critical dose for amorphization. (C) 2001 Published by Elsevier Science B.V. [References: 100]
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