Ion implantation in titanium dioxide thin films studied by perturbed angular correlations

The local environment in titanium dioxide was studied by the time dependent perturbed $\gamma\gamma$ angular correlation of $^{111}In/^{111}Cd$ and $^{181}Hf/^{181}Ta$ at the Helmholtz-Institut fur Strahlen-und Kernphysik, Bonn. An introduction to the implantation methodologies performed at the Bonn Radioisotope Separator is presented. The investigation was carried out on thin films, which were deposited by magnetic sputtering on Si. The results show two different sites for both probe nuclei with unique electric quadrupole interaction. Using $^{111}Cd$ one of them has been attributed to the substitutional Ti at the rutile structure. For $^{181}Ta$, the spectra show the anatase phase, with a well-defined electric quadrupole frequency.