Nature of the bonding, surface relaxation and charge transfer of Au dimmers on an MgO(100) surface

• Autores: C. Quintanar, R. Caballero, J. Ulises Reveles, S.N. Khanna
• Localización: Revista Mexicana de Física, ISSN-e 0035-001X, Vol. 58, Nº. 1, 2012, págs. 77-85
• Idioma: inglés
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• Resumen

  • First principles electronic structure investigation of he nature of adsorption, relaxation of the atoms near the adsorption site, and the charging of eh Au_(2) particle on the relaxed-rumpled MgO(100) surface have been carried out within the density functional theory-cluster-embedding approach. The investigations focus on an Au_(2) molecule, perpendicular to the surface, adsorbed at different locations. Three bonding sites are studied: a five coordinated oxygen regular terrace site O_(5c), an F_(8) neutral color center (two electrons in an O vacancy), and an F^(+)_(8) positive charged color center (one electron in an O vacancy). The studies indicate that large relaxation of the neighboring atoms and large charge transfer occurs for an Au_(2) over the color center. An analysis of the one-electron energy levels of the Au dimer, the MgO surface and the Au_(2)MgO(100) complex for each absorption site allows us to rationalize the nature of the bonding, surface relaxation, calculated absorption and dimerization energies and electron charge transfers.