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

Journal Article · Wed Jun 01 04:00:00 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, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 1336; ISSN 0094-243X; ISSN APCPCS
• Country of Publication: United States
• Language: English

Related Subjects

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