Abstract
Electron stimulated modifications of the rutile TiO2(110) surface have been investigated using scanning tunnelling microscopy tip pulses and electron beam irradiation. Tip pulses on the ‘as-prepared’ surface induce local surface reconstruction and removal of surface hydroxyls in a region around the reconstruction. A defocused beam from an electron gun as well as tip pulses have been used to generate a number of oxygen deficient surfaces. All tip pulse features display an oval profile, which can be attributed to the anisotropic conductivity of the TiO2(110) surface. A novel oxygen deficient phase with well-ordered defective ‘nano-cracks’ has been identified, which can be produced by either electron beam irradiation or low flash anneal temperatures (∼570 K). Annealing such surfaces to moderate temperatures (∼850 K) leads to mixed 1 × 1 and 1 × 2 surfaces, until now only achievable by annealing in oxygen or ageing by repeated sputter/anneal cycles. Heating to normal preparation temperatures (1000 K) reforms the clean, well-ordered 1 × 1 surface termination. Our results demonstrate the potential of electron induced processes to modify the oxygen composition and structure of the TiO2(110) surface in a controllable and reversible way for selective surface patterning and surface reactivity modification.
Highlights
The wide-scale implementation of nanotechnology relies on the development of highly controllable and reproducible procedures to fabricate nanoscale objects
Our results demonstrate the potential of electron induced processes to modify the oxygen composition and structure of the TiO2(110) surface in a controllable and reversible way for selective surface patterning and surface reactivity modification
The scanning tunnelling microscopy (STM) features associated with the 1 × 1 and 1 × 2 terminations as well as steps form the key structural motifs that are found on the modified surfaces
Summary
The wide-scale implementation of nanotechnology relies on the development of highly controllable and reproducible procedures to fabricate nanoscale objects. Typical STM images recorded from the inner beam region of e-exp 2 after this anneal are shown in figure 5. Surface cracks like those observed in the outer e-beam region in figure 6 are seen.
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