Kantorovich, LN;
Livshits, AI;
Stoneham, AM;
(2000)
Electrostatic energy calculation for the interpretation of scanning probe microscopy experiments.
Journal of Physics: Condensed Matter
, 12
(6)
795 - 814.
10.1088/0953-8984/12/6/304.
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Abstract
We discuss the correct expression for the classical electrostatic energy used while analysing scanning probe microscopy (SPM) experiments if either a conducting tip or a substrate or both are used in the experiment. For this purpose a general system consisting of an arbitrary arrangement of finite metallic conductors at fixed potentials (maintained by external sources) and a distribution of point charges in free space are considered using classical electrostatics. We stress the crucial importance of incorporating into the energy the contribution coming from the external sources (the `battery'). Using the Green function of the Laplace equation, we show in a very general case that the potential energy of point charges which are far away from metals is equally shared by their direct interaction and the polarization interaction due to charge induced in metals by the remote charges (the image interaction). When the charges are located close to the metals, there is an additional negative term in the energy entirely due to image interaction. The exact Hamiltonian of a quantum system interacting classically with polarized metal conductors is derived and its application in the Hartree-Fock and the density functional theories is briefly discussed. As an illustration of the theory, we consider an interaction of several point charges with a metal plane and a spherical tip, based on the set-up of a real SPM experiment. We show the significance of the image interaction for the force imposed on the tip.
Type: | Article |
---|---|
Title: | Electrostatic energy calculation for the interpretation of scanning probe microscopy experiments |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1088/0953-8984/12/6/304 |
Publisher version: | http://dx.doi.org/10.1088/0953-8984/12/6/304 |
Language: | English |
Additional information: | Text made available to UCL Discovery by kind permission of IOP Publishing, 2012 |
Keywords: | energy, Microscopy, Physics, PROBE, SURFACE, Surface Probe Microscopy |
UCL classification: | UCL UCL > Provost and Vice Provost Offices UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences |
URI: | https://discovery.ucl.ac.uk/id/eprint/24752 |
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