Defect sites generated by low energy Ar* bombardment (0.5-1.5 keV) at room
temperature and the effect of subsequent annealing were studied on a TiO2 (
1 1 0)-(1 x 2) surface by STM. It was found that, due to the effect of ion
bombardment, the row structure of the reconstructed TiO2 (1 1 0)-(1 x 2) su
rface transforms into a granular structure where the OD nanodots exhibit a
rather narrow size-distribution at about the diameter of 2 nm. The ordering
of these dots can be induced by a slight thermal treatment at 500-700 K re
sulting in 1D strings along the crystallographic orientation of [0 0 1]. In
this stage the surface terraces show (1 x 1) structure. Due to the effect
of further annealing at 900 K the surface converts into a (1 x 2) reconstru
cted arrangement. The latter process is accompanied by the dissolution of t
he out-rising dots and strings formed in the previous treatments. It is ass
umed that the composition of the uniform nanodots is probably (Ti2O3)(n) wh
ere n varies between 4 and 6. (C) 2001 Elsevier Science Ltd. All rights res
erved.