Studies Of Oxidation And Thermal Reduction Of The Cu(100) Surface Using Positron Annihilation Induced Auger Electron Spectroscopy

Journal Article · Wed Jun 01 00:00:00 EDT 2011 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3586147· OSTI ID:21513405

Fazleev, N G ^[1]; Nadesalingam, M P; Maddox, W; Weiss, A H ^[1]

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1. Department of Physics, University of Texas at Arlington, Arlington, Texas 76019 (United States)

Positron annihilation induced Auger electron spectroscopy (PAES) measurements from the surface of an oxidized Cu(100) single crystal show a large increase in the intensity of the annihilation induced Cu M2,3VV Auger peak as the sample is subjected to a series of isochronal anneals in vacuum up to annealing temperature 300 deg. C. The PAES intensity then decreases monotonically as the annealing temperature is increased to {approx}550 deg. C. Experimental positron annihilation probabilities with Cu 3p and O 1s core electrons are estimated from the measured intensities of the positron annihilation induced Cu M{sub 2,3}VV and O KLL Auger transitions. PAES results are analyzed by performing calculations of positron surface states and annihilation probabilities of the surface-trapped positrons with relevant core electrons taking into account the charge redistribution at the surface and various surface structures associated with low and high oxygen coverages. The variations in atomic structure and chemical composition of the topmost layers of the oxidized Cu(100) surface are found to affect localization and spatial extent of the positron surface state wave function. The computed positron binding energy and annihilation characteristics reveal their sensitivity to charge transfer effects, atomic structure and chemical composition of the topmost layers of the oxidized Cu(100) surface. Theoretical positron annihilation probabilities with Cu 3p and O 1s core electrons computed for the oxidized Cu(100) surface are compared with experimental ones. The obtained results provide a demonstration of thermal reduction of the copper oxide surface after annealing at 300 deg. C followed by re-oxidation of the Cu(100) surface at higher annealing temperatures presumably due to diffusion of subsurface oxygen to the surface.

• OSTI ID: 21513405
• Journal Information: AIP Conference Proceedings, Vol. 1336, Issue 1; Conference: CAARI 2010: 21. International Conference on the Application of Accelerators in Research and Industry, Fort Worth, TX (United States), 8-13 Aug 2010; Other Information: DOI: 10.1063/1.3586147; (c) 2011 American Institute of Physics; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANNEALING
ANNIHILATION
AUGER ELECTRON SPECTROSCOPY
BINDING ENERGY
CHARGE EXCHANGE
CHEMICAL COMPOSITION
COPPER
COPPER OXIDES
DIFFUSION
ELECTRONS
LAYERS
MONOCRYSTALS
OXIDATION
OXYGEN
POSITRONS
SENSITIVITY
SURFACES
TRAPPING
WAVE FUNCTIONS
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
CHALCOGENIDES
CHEMICAL REACTIONS
COPPER COMPOUNDS
CRYSTALS
ELECTRON SPECTROSCOPY
ELEMENTARY PARTICLES
ELEMENTS
ENERGY
FERMIONS
FUNCTIONS
HEAT TREATMENTS
INTERACTIONS
LEPTONS
MATTER
METALS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PARTICLE INTERACTIONS
SPECTROSCOPY
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS