Source-wave angular-momentum effects on electron-diffraction patterns

Journal Article · Sun Nov 15 04:00:00 EST 1992 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.46.13548· OSTI ID:7028542

Barton, J J ^[1]; Terminello, L J ^[2]

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1. IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598 (United States)
2. Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

We use a simple model to predict when electron-emission diffraction patterns from surfaces will have peaks or dips along internuclear axes. A high angular-momentum electron wave emitted from an atom acts like an {ital s} wave ({ital l}=0) in an extra centrifugal potential. This extra potential changes the electron's effective wave number and phase shift, altering the conditions for constructive interference when this wave scatters from nearby atoms. We demonstrate that the difference in source-wave angular momentum between Cu {ital M}{sub 2,3}{ital M4,5}{ital M4,5} Auger and Cu 3{ital p} photoelectrons explains the difference between their emission angular distributions from surfaces: the Auger-electron emission has a predominantly {ital f}-like source wave ({ital l}=3) and destructive interference in the forward electron-scattering direction ( silhouette'') while the photoelectron has lower angular momentum and constructive interference ( peak''). As long as this effect is considered, Auger-electron emission patterns can be used to determine surface structures. The unusual Auger-electron emission patterns observed by Frank {ital et} {ital al}. (Science 247, 182 (1990)) can be explained as due to high source-wave angular momentum and low electron energy.

• OSTI ID: 7028542
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 46:20; ISSN PRBMD; 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
ANGULAR MOMENTUM
AUGER EFFECT
COHERENT SCATTERING
COPPER
DIFFRACTION
DISTRIBUTION
ELECTRON DIFFRACTION
ELEMENTS
EMISSION
INTERFERENCE
METALS
PHOTOEMISSION
SCATTERING
SECONDARY EMISSION
SURFACES
TRANSITION ELEMENTS