The molecular dynamics technique was used to determine the threshold displacement energies along different crystallographic directions for Si and C atoms in SiC, also allowing for irradiation temperature effects, and to study in detail the mechanisms of atomic displacement production. For this purpose, the widely tested Tersoff potential, implemented in a molecular dynamics code optimized to study the interaction of high-energy ions with crystals, was used to describe the interatomic forces in SiC. It was found that it was difficult to define a single threshold for this material. Instead, the introduction of two thresholds, upper and lower, became necessary. These two thresholds delimit an uncertainty band, within which the displacement may or may not be produced, because the Frenkel pairs generated in such a transferred-kinetic-energy range were metastable. The Arrhenius law expressing the lifetime of one of these metastable defects has also been deduced from the simulation. Finally, on the basis of the results of the simulation, possible values for the recombination distance and the average threshold energy were proposed.

Basic Mechanisms of Atomic Displacement Production in Cubic Silicon Carbide - a Molecular Dynamics Study. L.Malerba, J.M.Perlado: Physical Review B, 2002, 65[4], 045202 (10pp)