Identification of Irradiation-Induced Al-Mn Dumbbells in Al Crystals by Backscattering

By measuring the energy spectra of backscattered 1-MeV ${\mathrm{He}}^{+}$ ions from Al-0.09 at.% Mn crystals, it was found that Mn atoms were displaced from lattice sites by irradiation with 0.3-1.0-MeV ${\mathrm{He}}^{+}$ ions at 35°K. Annealing results and an analysis of $〈110〉$ and $〈111〉$ axial channeling and {100} planar channeling indicated that the Mn atoms were displaced by trapping irradiation-induced interstitial Al atoms, forming Al-Mn atom pairs in the $〈100〉$ dumbbell configuration.