We have used non-contact atomic force microscopy (NC-AFM) to study TiO2(110
), identifying a row with twice the thickness of a TiO2(110)1 X 2 row. This
can be explained by a [1 (1) over bar 0] extension of the added row model
of TiO2(110)1 X 2. In the [001] direction, this reconstruction narrows into
a 1 X 2 row giving strong evidence that the two structures are very closel
y related. For the TiO2(100) surface, we present NC-AFM data which supports
the intermediate 1 X 3-beta model previously proposed on the basis of an S
TM experiment. (C) 2000 Elsevier Science B.V. All rights reserved.