S. A. Haycock

Growth of copper and palladium on α-Al2O3(0001)

Non-contact atomic force microscopy (NC-AFM) has been used to image the room-temperature growth of copper and palladium on the (1 x 1) and (root 31 x root 31) R +/- 9 degrees terminations of alpha-Al2O3(0001). Three-dimensional (3D) clusters of palladium are observed on both the (1 x 1) and the (root 31 x root 31) R +/- 9 degrees terminations, with 3D clusters of copper observed on the reconstructed surface. There is evidence of step-edge-dominated growth of palladium on the (root 31 x root 31) R +/- 9 degrees termination

Imaging reconstructed TiO2 surfaces with non-contact atomic force microscopy

Abstract 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)1×2 row. This can be explained by a [110] extension of the added row model of TiO2(110)1×2. In the [001] direction, this reconstruction narrows into a 1×2 row giving strong evidence that the two structures are very closely related. For the TiO2(100) surface, we present NC-AFM data which supports the intermediate 1×3-β model previously proposed on the basis of an STM experiment.

Non-contact atomic force microscopy imaging of TiO2(100) surfaces

Abstract Atomically resolved non-contact fm mode atomic force microscopy images have been obtained from TiO2(100) surfaces. The 1×1 surface is observed, as well as the 1×3 phase previously imaged with STM. The morphology of the latter reconstruction consists of (110) microfacets. An additional reconstruction with 1×3 symmetry is observed, which is assigned to a phase intermediate between the 1×1 and 1×3-microfacet terminations.

A non-contact atomic force microscopy and ‘force spectroscopy’ study of charging on oxide surfaces

Force spectroscopy curves from a number of oxide surfaces have been recorded. Contact potential difference (CPD) curves recorded from two different areas of an MgO(100) surface are shifted in a manner consistent with local surface charging. This charging is removed by deposition of Fe or Cu. On an NiAl(110) supported alumina film we have investigated the use of frequency shift (Δf) versus distance curves as an analytical tool for chemical identification. Curves recorded from the bare substrate are clearly different to those recorded over adsorbates. This difference is likely to be due to local surface charging, since such differences are not observed in detuning curves recorded from domain boundaries of similar apparent height to the adsorbates.