Study on the annealing effects of proton-implanted rutile

The annealing effects of proton-implanted rutile single crystal have been investigated with positron annihilation technology (PAT). The stoichiometric and non-stoichiometric rutile crystals were implanted by protons, with an energy of 4.9 MeV and a fluence of 1×1018 m−2. Implanted samples were annealed from room temperature to 500 °C with steps of 50 °C. Positron annihilation lifetime spectra were used to study the dynamic variation of defects. Corresponding optical absorption spectra were also measured for comparison. The results show that, implanted H+ ions induce defects being different in stoichiometric and non-stoichiometric samples. The defects aggregate to bigger, complex clusters during annealing, then decompose into small, simple defects again. The aggregating temperature of different defects is different. For non-stoichiometric rutile, the results of PAT measurements are satisfactorily consistent with those of optical absorption. The mechanism of annealing effects is also discussed.