It was recalled that the damage distribution in implanted crystalline oxides often exhibited 2 sub-peaks; one near to the surface and one near to the mean projected range of the implanted ions. In the case of Hg-implanted rutile monocrystals, 2 well-separated peaks were observed in <001>-, <111>- and <100>-oriented crystals. Implantation at 77 or 300K, followed by annealing, was used to study the mechanisms of near-surface peak formation. It was shown that this peak was located exactly at the surface. Long-range atomic migration, pinning at the surface, and changes in composition due to preferential O sputtering, were excluded as being sources of surface-damage peak-formation. Recovery of this peak was not observed at temperatures below 300K; unlike damage near to the mean projected range, which recovered by about 65%. Recovery of both sub-peaks occurred at temperatures above 500K.

Lattice Disorder Distribution and Recovery in Hg Implanted TiO2. Khubeis, I., Meyer, O.: Nuclear Instruments and Methods in Physics Research B, 1996, 120[1-4], 257-61