On the annihilation of a frenkel defect by low energetic atomic collisions

Frenkel defect annihilation induced by sub-threshold irradiation was studied by simulating low energetic atomic collisions in the neighbourhood of a Frenkel defect in computer model calculations. The fcc model crystal contained 446 atoms. The interaction between the atoms was described by a pairwise interaction Morse potential.The [100] split interstitial configuration was found to be stable and surrounded by 62 lattice sites at which a vacancy recombines spontaneously with the interstitial. For at least another 24 lattice sites it was shown that the Frenkel defect recombines if a kinetic energy of 0.1 eV is transferred to one of the atoms of the interstitial configuration or to certain atoms in the neighbourhood of the defect. A few recombination processes are discussed in detail. The number of the above mentioned lattice sites is compared with experimental data.