Investigation of radiation induced defect impurity complexes in aluminium alloys by channeling A critical analysis by computer simulation

Abstract

The flux distributions of channeled He + ions in Al and their development with penetration depth are calculated for the major axial and planar directions using Monte Carlo simulations. A strong depth oscillation of the flux in the channel center is observed in the near surface region indicating the statistical nonequilibrium of the flux. The Monte Carlo program is applied to evaluate published yields measured in different directions (〈100〉, 〈110〉, 〈111〉, {100}, {111}) of He + irradiated Al alloys. It is shown that the solute atoms Mn, Cu, Zn, Ge, and Ag which react with irradiation induced self-intersitials are displaced from their lattice site into the 〈100〉 or 〈111〉 direction. The distance of the displaced atoms to the octahedral interstitial site is found to be less than 0.1 nm. The displacement of the solute atom in the 〈100〉 direction agrees quite well with published analytically determined values. A decision which kind of the 〈100〉 or 〈111〉 mixed dumbbell configuration does exist is not possible. It requires the knowledge of the correct mixed dumbbell concentration.