Effect of heavy ion irradiation on near-surface microstructure in single crystals of rutile TiO2

Radiation damage near the surface of rutile (TiO2) single crystals irradiat ed with 360keV Xe2+ ions has been studied by combining Rutherford backscatt ering spectroscopy and ion channelling (RBS/C) analyses with direct observa tions using transmission electron microscopy (TEM). Irradiations were perfo rmed at ambient temperature on TiO2 single crystal surfaces with (110) and (100) orientations, using ion fluences of up to 7 x 10(19) Xe ions m(-2). T he RBS/C spectra revealed two damage peaks: one peak due to a surface damag e layer and a second peak due to a buried damage layer near the mean projec ted range of the implanted ions. Cross-sectional TEM and high-resolution el ectron microscopy revealed that the surface damage layer consists of TiO2 c rystallites with different orientations compared with the original single c rystal.