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Structure and apparent topography of TiO2 (110) surfaces

Kwok-On Ng·David Vanderbilt
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Abstract

We present self-consistent ab-initio total-energy and electronic-structure calculations on stoichiometric and non-stoichiometric TiO2 (110) surfaces. Scanning tunneling microscopy (STM) topographs are simulated by calculating the local electronic density of states over an energy window appropriate for the experimental positive-bias conditions. We find that under these conditions the STM tends to image the undercoordinated Ti atoms, in spite of the physical protrusion of the O atoms, giving an apparent reversal of topographic contrast on the stoichiometric 1x1 or missing-row 2x1 surface. We also show that both the interpretation of STM images and the direct comparison of surface energies favor an added-row structure over the missing-row structure for the oxygen-deficient 2x1 surface.

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Kwok-On Ng, David Vanderbilt. 1997-05-25. Structure and apparent topography of TiO2 (110) surfaces. https://doi.org/10.1103/physrevb.56.10544

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