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Title: Azimuth-dependent Auger neutralization of He{sup +} on Ag(111) and (110) surfaces

Abstract

We present a detailed theoretical analysis of the role played by s and d electrons in Auger neutralization processes of He{sup +} at Ag(111) and Ag(110) surfaces. We calculate crystal-lattice-site Auger neutralization rates as a function of the perpendicular distance between ions and surfaces. We find that the rate is very insensitive to the lateral position for large values of the perpendicular distance because the contribution of the delocalized s electrons dominates in this case. In contrast, the contribution of d electrons dominates at short perpendicular distances and the strong spatial localization of these electrons causes a similar strong dependence of the Auger rate with lateral position. We perform molecular dynamic simulations of scattered ion trajectories, which, used together with the Auger neutralization rates, allow us to obtain the theoretical ion fraction that we compare with our measurements. This parameter-free theory is able to reproduce the magnitude of the ion survival probability and its dependence with the azimuthal angle of incidence for both surfaces of Ag, thus showing the important role played by localized electrons in Auger neutralization of He.

Authors:
;  [1];  [1];  [2];  [3]
  1. Departamento de Fisica Teorica de la Materia Condensada, Universidad Autonoma de Madrid, E-28049 Madrid (Spain)
  2. (Spain)
  3. Laboratoire des Collisions Atomiques et Moleculaires, Universite Paris Sud, 91405 Orsay (France)
Publication Date:
OSTI Identifier:
20957820
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. B, Condensed Matter and Materials Physics; Journal Volume: 75; Journal Issue: 16; Other Information: DOI: 10.1103/PhysRevB.75.165404; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; AUGER EFFECT; COMPARATIVE EVALUATIONS; CRYSTAL LATTICES; ELECTRONS; HELIUM IONS; INCIDENCE ANGLE; SILVER 110; SILVER 111; SIMULATION; SURFACES

Citation Formats

Valdes, Diego, Monreal, R. C., Blanco, J. M., European Space Astronomy Centre, ESAC-ESA, Ingenieria y Servicios Aeroespaciales, and Esaulov, V. A. Azimuth-dependent Auger neutralization of He{sup +} on Ag(111) and (110) surfaces. United States: N. p., 2007. Web. doi:10.1103/PHYSREVB.75.165404.
Valdes, Diego, Monreal, R. C., Blanco, J. M., European Space Astronomy Centre, ESAC-ESA, Ingenieria y Servicios Aeroespaciales, & Esaulov, V. A. Azimuth-dependent Auger neutralization of He{sup +} on Ag(111) and (110) surfaces. United States. doi:10.1103/PHYSREVB.75.165404.
Valdes, Diego, Monreal, R. C., Blanco, J. M., European Space Astronomy Centre, ESAC-ESA, Ingenieria y Servicios Aeroespaciales, and Esaulov, V. A. Sun . "Azimuth-dependent Auger neutralization of He{sup +} on Ag(111) and (110) surfaces". United States. doi:10.1103/PHYSREVB.75.165404.
@article{osti_20957820,
title = {Azimuth-dependent Auger neutralization of He{sup +} on Ag(111) and (110) surfaces},
author = {Valdes, Diego and Monreal, R. C. and Blanco, J. M. and European Space Astronomy Centre, ESAC-ESA, Ingenieria y Servicios Aeroespaciales and Esaulov, V. A.},
abstractNote = {We present a detailed theoretical analysis of the role played by s and d electrons in Auger neutralization processes of He{sup +} at Ag(111) and Ag(110) surfaces. We calculate crystal-lattice-site Auger neutralization rates as a function of the perpendicular distance between ions and surfaces. We find that the rate is very insensitive to the lateral position for large values of the perpendicular distance because the contribution of the delocalized s electrons dominates in this case. In contrast, the contribution of d electrons dominates at short perpendicular distances and the strong spatial localization of these electrons causes a similar strong dependence of the Auger rate with lateral position. We perform molecular dynamic simulations of scattered ion trajectories, which, used together with the Auger neutralization rates, allow us to obtain the theoretical ion fraction that we compare with our measurements. This parameter-free theory is able to reproduce the magnitude of the ion survival probability and its dependence with the azimuthal angle of incidence for both surfaces of Ag, thus showing the important role played by localized electrons in Auger neutralization of He.},
doi = {10.1103/PHYSREVB.75.165404},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
number = 16,
volume = 75,
place = {United States},
year = {Sun Apr 15 00:00:00 EDT 2007},
month = {Sun Apr 15 00:00:00 EDT 2007}
}