LATTICE DISORDER DISTRIBUTION AND RECOVERY IN HG IMPLANTED TIO2

The damage distribution of ion implanted crystalline oxides often reve als two subpeaks, one near the surface and one near the mean projected range, R(p), of the implanted ions. For Hg implanted TiO2 (rutile) si ngle crystals two well separated peaks were observed for [001], [111] and [100] oriented crystals. Implantations at 77 K and 300 K, followed by annealing experiments were performed to study the mechanisms of ne ar surface peak formation. It was shown that this peak is exactly loca ted at the surface. Long range atomic migration and pinning at the sur face as well as changes of the composition by preferential oxygen sput tering could be excluded as sources of surface damage peak formation. A recovery of this peak was not observed below 300 K, in contrast to t he damage near R(p), which recovered by about 65%. Recovery of both su bpeaks were noted, however, at temperatures of 500 K and above.