Low-energy positron diffraction from GaAs(110)

Journal Article · Wed Jul 01 04:00:00 EDT 1992 · Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States)

DOI:https://doi.org/10.1116/1.578104· OSTI ID:7039440

Lessor, D L ^[1]; Duke, C B ^[2]; Chen, X M; Brandes, G R; Canter, K F ^[3]; Ford, W K ^[4]

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1. Pacific Northwest Laboratory, K5-17 ISB-1, Richland, Washington 99352 (United States)
2. Xerox Webster Research Center, 800 Phillips Road, 0114-38D, Webster, New York 14580 (United States)
3. Department of Physics, Brandeis University, Waltham, Massachusetts 02254 (United States)
4. Advanced Materials Center and Department of Physics, Montana State University, Bozeman, Montana 59717 (United States)

Intensities of 16 beams of near normal incidence positrons have been measured at {ital T}=120 K and analyzed using a multiple scattering model of the low-energy positron diffraction (LEPD) process. Excellent correspondence between the measured and calculated intensities is obtained for a reconstruction that is primarily a bond-length-conserving rotation of the top layer, with As relaxed outward and Ga inward with a tilt angle {omega}{sub 1} = 28.6 {plus minus} 3{degree}, confirming the results of previous structure analyses for this surface. The quality of the description of the measured intensities, as measured by the x-ray {ital R} factor, is significantly better for LEPD than for low-energy electron diffraction. This result is attributed to the repulsive character of the positron-ion core potential and a resulting more surface sensitive diffraction process for LEPD.

• DOE Contract Number: AC06-76RL01830
• OSTI ID: 7039440
• Journal Information: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States), Journal Name: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States) Vol. 10:4; ISSN 0734-2101; ISSN JVTAD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
665300 -- Interactions Between Beams & Condensed Matter-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ARSENIC COMPOUNDS
ARSENIDES
BOND LENGTHS
COHERENT SCATTERING
COLLISIONS
DIFFRACTION
DIMENSIONS
ELECTRON DIFFRACTION
ENERGY RANGE
EV RANGE
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
LENGTH
MULTIPLE SCATTERING
PNICTIDES
POSITRON COLLISIONS
SCATTERING
SURFACE PROPERTIES