The interaction of a point charge with a metal surface: theory and calculations for (111), (100) and (110) aluminium surfaces

Finnis, Michael W.; Kaschner, R.; Kruse, C.; Furthmüller, J.; Scheffler, Matthias

doi:10.1088/0953-8984/7/10/009

Cited by 51 publications

(36 citation statements)

References 20 publications

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“…This is what we have in mind when we use the term "image effect" in the following discussion. For a deeper discussion of this problem we refer to Scheffler and Bradshaw (1983), Finnis et al (1995), and references therein. Figure 5.17 shows that the description of partial ionization of the Na adatom and building up a screening charge in the substrate remains qualitatively valid when the alkali-metal atom is adsorbed.…”

Section: Ionization Of the Adsorbate And Screening By The Substrate Ementioning

confidence: 99%

Theory of Adsorption on Metal Substrates

Scheffler

Stampfl

2000

Electronic Structure

103

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Section: Ionization Of the Adsorbate And Screening By The Substrate Ementioning

confidence: 99%

Theory of Adsorption on Metal Substrates

Scheffler

Stampfl

2000

Electronic Structure

103

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“…Other techniques to introduce image effects in classical MD simulations have been proposed in the literature. An approach (called discrete classical model, DCM) has been developed by Finnis et al,32, 34 and recently applied to the simulations of isopropanol on Pt(111) surface 35. The essence of the method is to represent the polarization of the metal via induced charges and dipoles on each metal atom.…”

Section: Introductionmentioning

confidence: 99%

Including image charge effects in the molecular dynamics simulations of molecules on metal surfaces

Iori

Corni²

2008

J Comput Chem

118

202

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Combinatorial bio-techniques have demonstrated that proteins can be good and even selective binders for several inorganic surfaces, including metals. However, the understanding of the basic physical mechanisms that govern such interactions did not keep up with the success in these experiments. The comprehension of such mechanisms would greatly benefit from the computational investigation of the problem. Because of the complexity of the system, classical molecular dynamics simulations based on an atomistic description appear to be the best compromise between reliability and feasibility. For proteins interacting with metal surfaces, however, methodological improvements with respect to standard Molecular Dynamics (MD) of proteins are needed, since the polarization of the metal induced by the protein (and the surrounding water) is not generally negligible. In this article, we present a simple approach to introduce metal polarization effects (often termed image effects) in MD simulations by exploiting standard features of bio-oriented MD codes such as the widely used GROMACS and NAMD. Tests to show the reliability of the proposed methods are presented, and the results for a model application showing the importance of image effects are also discussed.

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“…Two different models have been brought forth to describe the interfacial bond energy. In one of them the electrostatic image charges between the oxide ions and the metallic surface are made responsible for the bonding [2,3]. Other models favor a hybridization effect between the oxygen p-and the metal d-orbitals, which may lead to a slightly covalent or ionic bond at the interface [4,5].…”

mentioning

confidence: 99%

Extraordinary Adhesion of Niobium on Sapphire Substrates

et al. 1997

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We have investigated the adhesion between a metal and a ceramic interface, in particular between Nb(110) films and Al 2 O 3 ͑1120͒ substrates. We have tested the adhesion properties by hydrogen loading of the metal film. The resulting strains were measured by in-and out-of-plane lattice parameter measurements. In contrast to the bulk behavior, we find for hydrogen in thin Nb films a highly anisotropic in plane strain. Comparing the in-plane expansion with the free case, we observe a tensile stress exceeding the yield stress of bulk Nb by at least a factor of 10. This unusually large resistance against expansion is due to giant adhesive forces at the metal/ceramic interface.[S0031-9007(97)04843-6] PACS numbers: 68.60.Bs, Understanding adhesion properties of metals on ceramic substrates is one of the most intriguing and important topics of current materials research [1]. High temperature composite materials, corrosion resistant coatings, and electronic packaging rely on the adhesive strength of metal/ ceramic interfaces. Two different models have been brought forth to describe the interfacial bond energy. In one of them the electrostatic image charges between the oxide ions and the metallic surface are made responsible for the bonding [2,3]. Other models favor a hybridization effect between the oxygen p-and the metal d-orbitals, which may lead to a slightly covalent or ionic bond at the interface [4,5]. The latter model requires a well-defined epitaxial relationship at the metal/ceramic interface, whereas the former is independent of specific atomic coordinations. In practice, good adhesion has been observed at both, heteroepitaxial pseudomorphic, as well as amorphous metal/ceramic interfaces. Therefore, a decision in favor of one or the other model is difficult to make.Niobium thin films on sapphire substrates can be considered as a model system for studying adhesion properties between metals and ceramics. The growth of Nb on sapphire has been studied in much detail recently and the epitaxial relation is well understood [6][7][8][9][10][11]. The Nb͞Al 2 O 3 interface can be described by a unique threedimensional epitaxy characterized the following orientational relationships [7-10]:Nb grows on the sapphire substrate almost strain free and forms a highly ordered crystal structure with large structural coherence lengths [12,13]. The residual epitaxial strain which depends on the film thickness is usually less than 0.05%. Small amounts of hydrogen may help to release residual stresses and the crystal structure becomes even more perfect due to a "cold" annealing effect [14]. Furthermore, Nb and sapphire have nearly the same thermal expansion coefficients [15]. Therefore thermal strains are not confused with epitaxial or applied strains.Measuring the adhesion of an epitaxial film is not an easy task. Usually the films are bent together with the substrate and the critical radius of curvature is determined before the film lifts off [16]. We have probed the adhesion properties of the metal/oxide interface in a different ...

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The interaction of a point charge with a metal surface: theory and calculations for (111), (100) and (110) aluminium surfaces

Cited by 51 publications

References 20 publications

Theory of Adsorption on Metal Substrates

Theory of Adsorption on Metal Substrates

Including image charge effects in the molecular dynamics simulations of molecules on metal surfaces

Extraordinary Adhesion of Niobium on Sapphire Substrates

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