Please use this identifier to cite or link to this item: http://buratest.brunel.ac.uk/handle/2438/11024
Title: A first principles simulation framework for the interactions between a Si(001) surface and a scanning probe
Authors: Ly, DQ
Makatsoris, C
Keywords: DFT;Si(001)-p(2 × 1), p(2 × 2), c(4 × 2);Scanning probe microscopy;Phase transitions;Dimer toggling
Issue Date: 2012
Publisher: Scientific Research
Citation: Journal of Surface Engineered Materials and Advanced Technology, 2(3A): 194-202, (July 2012)
Abstract: By means of total energy calculations within the framework of the local density approximation (LDA), the interactions between a silicon Si(001) surface and a scanning probe are investigated. The tip of the probe, comprising 4 Si atoms scans along the dimer lines above an asymmetric p(2 × 1) surface, at a distance where the chemical interaction between tip-surface is dominant and responsible for image resolution. At that distance, the tip causes the dimer to toggle when it scans above the lower atom of a dimer. The toggled dimers create an alternating pattern, where the immediately adja-cent neighbours of a toggled dimer remain unchanged. After the tip has fully scanned across the p(2 × 1) surface, causes the dimers to arrange in a p(2 × 2) reconstruction, reproducing the images obtained in scanning probe experiments. Our modelling methodology includes simulations that reveal the energy input required to overcome the barrier to the onset of dimer toggling. The results show that the energy input to overcome this barrier is lower for the p(2 × 1) surface than that for the p(2 × 2) or c(4 × 2) surfaces.
URI: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=21429
http://bura.brunel.ac.uk/handle/2438/11024
DOI: http://dx.doi.org/10.4236/jsemat.2012.223030
ISSN: 2161-4881
Appears in Collections:Dept of Mechanical Aerospace and Civil Engineering Research Papers

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