Charge transfers at metal/oxide interfaces: a DFT study of formation of K delta+ and Au delta- species on MgO/Ag(100) ultra-thin films from deposition of neutral atoms.

Full Abstract

Ultra-thin oxide films grown on a metal substrate and of thickness smaller than 1 nm may exhibit unusual properties with respect to thicker films or single crystal oxide surfaces. In a previous study [G. Pacchioni, L. Giordano and M. Baistrocchi, Phys. Rev. Lett., 2005, 94, 226104] we have suggested that a Au atom adsorbed on a MgO/Mo(100) thin film becomes negatively charged by direct electron tunneling from the Mo metal and that this is related to the low MgO/Mo(100) work function. Here we show, based on periodic DFT supercell calculations, that charge transfer can occur also in the opposite direction by adsorption of electropositive K atoms on MgO/Ag(100) films. We predict the occurrence of a charge transfer also for Au on MgO/Ag(100) films despite the fact that here the work function is 1 eV larger than in MgO/Mo(100). The formation of a layer of adsorbed negative (Au delta-/MgO/Ag) or positive (K delta+/MgO/Ag) adsorbates results in an increase or decrease, respectively, of the MgO/Ag(100) work function as predicted by the classical Gurney model for ionic adsorbates on metal surfaces.

Learn Faster Today Improve your study skills

Author information

Author/s: Giordano, Livia (L); Pacchioni, Gianfranco (G);

Affiliation: Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, via Cozzi, 53-20125, Milano, Italy.

Journal and publication information

Publication Type: Journal Article; Research Support, Non-U.S. Gov't

Journal: Physical chemistry chemical physics : PCCP (Phys Chem Chem Phys), published in England. (Language: eng)

Reference: 2006-Jul; vol 8 (issue 28) : pp 3335-41

Dates: Created 2006/07/12; Completed 2006/09/05; Revised 2008/11/21;

PMID: 16835682, status: MEDLINE (last retrieval date: 12/26/2008)

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

External Links for this article (including full text providers, if available):

Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.

This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.

MeSH headings (categories)

This article was linked to the MESH Headings shown below.

Computer Simulation
Crystallization - methods
Electron Transport
Gold - chemistry
Magnesium Oxide - chemistry
Membranes, Artificial
Metals - chemistry
Models, Chemical

Models, Chemical
Models, Molecular
Nanostructures - chemistry; ultrastructure
Nanotechnology - methods
Oxides - chemistry
Particle Size
Static Electricity
Surface Properties

Associated Chemicals: Membranes, Artificial (0) ; Metals (0) ; Oxides (0) ; Magnesium Oxide (1309-48-4) ; Gold (7440-57-5)

These are the highest related articles currently in the database:

See 100+ related articles.