La-, Sn- and Hf-implanted in TiO2 single crystals: Lattice disorder and lattice site location

Rutherford backscattering spectrometry and channeling were used to characterize the lattice disorder produced by implantation of La- Sn- and Hf-ions into TiO2 (rutile) single crystals and to determine their lattice site location. La-ions were implanted at substrate temperatures, T-i between 77 and 1100 K. Two recovery stages of the lattice disorder between 300 and 500 K and above 700 K have been observed. These stages are about 200 K lower than those observed for subsequent isochronal annealing of an amorphous TiO2 layer, This reveals the influence of radiation enhanced annealing, While for the as-implanted La no regular lattice site occupation was observed, high substitutional components of 100% and 95% have been measured for Sn and Hf, respectively, which are isoelectronic to Ti. Preliminary results for Sn and Hf, indicate that the size mismatch energy plays an important role for the lattice site occupation.