Damage evolution in Xe-ion irradiated rutile (TiO2) single crystals

Rutile (TiO2) single crystals with (110) and (100) orientations were irradi ated with 360 keV Xe-24 ions at 300 K to fluences ranging from 1 x 10(17) t o 5 x 10(20) Xe/m(2). Irradiated samples were analyzed using Rutherford bac kscattering spectroscopy combined with ion channeling analysis (RBS/C) and transmission electron microscopy (TEM). RBS/C results showed that much of t he instantaneous displacement damage produced under ion irradiation is reco vered under ambient temperature irradiation conditions. Upon irradiation to a fluence of 2 x 10(19) Xe/m(2), the radiation damage-induced microstructu re was observed by TEM to consist of three distinct layers: (1) a layer nea r surface (thickness about 12 nm) exhibiting relatively homogeneous TEM con trast; (2) a second layer with a low density of relatively large-sized defe cts; and (3) a third layer consisting of a high concentration of small defe cts. After the fluence was increased to 5 x 10(19) Xe/m(2), a buried amorph ous layer was observed by TEM. The thickness of the amorphous layer was fou nd to increase with increasing Xe ion fluence. The uppermost damage layer, which accounts for the surface subpeak in RBS/C spectra, was found to be po lygonized by ion irradiation. (C) 2000 Elsevier Science B.V. All rights res erved.