Low-energy ion-backscattering spectroscopies applied to the determination of surface structure

Thesis/Dissertation · Tue Jan 01 00:00:00 EST 1985

OSTI ID:5485205

Yarmoff, J A

Low-Energy Ion Scattering (LEIS) was investigated as a means for determining the geometric structure at a single-crystal surface. A three-dimensional Monte-Carlo computer simulation was developed and applied to existing LEIS data. The binary collision approximation was found to yield satisfactory results in simulating Buck's time-of-flight energy spectra for 2.4 keV Ne/sup +/ scattering from Ni(001). A two-atom-layer model was used in calculations of the azimuthal anisotropy of the ion yield measured by Bernheim and Slodzian for 9.5 keV Ne/sup +/ scattering from Cu(001). The calculations were successful in reproducing most of the features that had been observed in the experiments, which shows that this model contained most of the physics required to interpret the data. An apparatus for performing LEIS studies was built, and Low-Energy Ion-Backscattering Angular Distributions (LEIBAD) were collected with 3-20 keV /sup 6/Li/sup +/ incident on Cu(001). For incidence along a low-index Miller axis of the crystal, shadowing effects limited the penetration depth of the elastically scattered ions. However, neutralized Li atoms, which were not filtered out of the scattered yield by the high-pass filter, provided a background characteristic of the bulk. A high-resolution electrostatic analyzer was used to collect impact Collision Ion Scattering Spectroscopy (ICISS) data for 5-keV /sup 6/Li/sup +/ ions to study the Cu(110) and Cu(110) (2 x 1)-0 surfaces.

• Research Organization: California Univ., Los Angeles (USA)
• OSTI ID: 5485205
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COPPER
SURFACES
ION COLLISIONS
BACKSCATTERING
LITHIUM 6 BEAMS
NEON IONS
NICKEL
SHAPE
ANGULAR DISTRIBUTION
COMPUTERIZED SIMULATION
KEV RANGE 01-10
KEV RANGE 10-100
MEASURING METHODS
MONTE CARLO METHOD
THREE-DIMENSIONAL CALCULATIONS
BEAMS
CHARGED PARTICLES
COLLISIONS
DISTRIBUTION
ELEMENTS
ENERGY RANGE
ION BEAMS
IONS
KEV RANGE
METALS
SCATTERING
SIMULATION
TRANSITION ELEMENTS
640301* - Atomic
Molecular & Chemical Physics- Beams & their Reactions