Energy dependence of angular distributions of sputtered particles from the Ag[l brace]111[r brace] surface

Journal Article · Mon Nov 01 04:00:00 EST 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.48.12399· OSTI ID:5967694

Chang, C ^[1]

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1. Department of Chemistry, University of Hawaii, Honolulu, Hawaii 96822 (United States) Department of Chemistry, National Taiwan University, Taipei, Taiwan, Republi c of China (Taiwan, Province of China)

The angular distributions of Ag atoms ejected from a Ag[l brace]111[r brace] surface due to 2-keV Ar bombardment have been calculated from molecular-dynamics simulations of the particle impact event. For atoms ejected with kinetic energies of above 15 eV, the distributions are found to be sensitive to variations in the ejection energy. The direction along which the maximum sputter intensity is detected alternates between two different [l angle]211[r angle] azimuths as the kinetic energy of the ejected atom is increased. A time-exposure representation of the surface-collision cascade is introduced for examining the collision mechanisms that cause atoms to eject along specific crystallographic directions. It shows that, in addition to the presence of the open spacings between the first-layer surface atoms, there are subtle collision effects that determine the preferred direction of ejection. Atomic ejection along those [l angle]211[r angle] azimuths which have the non-close-packed row of atoms extending to the bulk is mainly induced by the up-down-, the head-on-, and the sideswipe-collision processes. The up-down-collision process may result in ejection of atoms at a distance of more than 20 A away from the point of the primary impact. Further, the low-energy atoms are usually emitted from the surface due to sideswipe collisions by the moving surface atoms. The dependence of the preferred direction of ejection on the collision time of the ejected atom is also discussed.

• OSTI ID: 5967694
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 48:17; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

665300* -- Interactions Between Beams & Condensed Matter-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANGULAR DISTRIBUTION
ARGON IONS
CHARGED PARTICLES
COMPUTERIZED SIMULATION
DISTRIBUTION
ELEMENTS
ENERGY DEPENDENCE
ENERGY RANGE
IONS
KEV RANGE
KEV RANGE 01-10
METALS
SILVER
SIMULATION
SPUTTERING
SURFACES
TRANSITION ELEMENTS