Accumulation and thermal recovery of disorder in Au2+-irradiated SrTiO3

Damage accumulation and thermal recovery processes have been investigated i n single crystal SrTiO3(100) irradiated with 1.0 MeV AU(2+) using in situ R utherford backscattering spectrometry in channeling geometry (RBS/C). Sampl es were irradiated at temperatures of 170 and 300 K with ion fluences rangi ng from 0.10 to 0.40 AU(2+) /nm(2). The in situ RBS/C analysis indicates th at the relative disorder shows a strong sigmoidal dependence on ion dose. A fter an ion fluence of 0.30 Au2+/nm(2) at 170 K, the buried region at the d amage peak (similar to 60 nm) becomes fully amorphous, which corresponds to a dose of similar to0.8 displacement per atom (dpa). For irradiation at 30 0 K, an ion fluence of 0.40 Au2+/nm(2) (similar to1.1 dpa) is necessary to achieve an amorphous state at the damage peak. An analysis of the defects d echanneling factor suggests that the irradiated regions consist mostly of i nterstitial atoms or amorphous clusters. In situ thermal annealing experime nts were performed to study damage recovery processes up to a maximum tempe rature of 870 K. The thermal recovery processes occur over a broad temperat ure range, and the disorder created by low ion fluences, 0.10-0.27 Au2+ /nm (2), is almost completely recovered after annealing at 870 K. (C) 2001 Publ ished by Elsevier Science B.V.