Monte Carlo study of variations in the surface sensitivity of energy-resolved x-ray absorption spectra from Ni/NiO thin-film bilayers

Journal Article · Fri Dec 15 00:00:00 EST 2006 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.74.245408· OSTI ID:20853983

Abbey, Brian; Lipp, John D; Barber, Zoe H; Rayment, Trevor ^[1]

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1. Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW (United Kingdom)

The variation in the surface sensitivity of the x-ray absorption electron yield as a function of energy has been investigated for a Ni/NiO thin film bilayer sample. Experimental data was obtained using a recently developed detector capable of making energy-resolved electron yield x-ray absorption spectroscopy (XAS) measurements at ambient pressure. Datasets obtained using this technique contain information about the relative phase contribution to the XAS at each incident photon energy. Analysis of the data thus provides detailed information about the variation in surface sensitivity as a function of energy. This 'surface sensitivity profile' is studied using Monte Carlo simulations which include inelastic scattering events and discrete energy loss processes. Consideration of the electron multiplication/propagation processes within the sample provides an insight into the principles behind electron-yield signal formation. The simulations accurately reproduce the experimentally determined fraction of NiO in the XAS down to sub-keV energies. The results provide a reliable method for the independent determination of layer thickness in stratified samples and will aid in the future development of the technique.

• OSTI ID: 20853983
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 74, Issue 24; Other Information: DOI: 10.1103/PhysRevB.74.245408; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
ABSORPTION SPECTROSCOPY
AUGER ELECTRON SPECTROSCOPY
COMPUTERIZED SIMULATION
ELECTRONS
ENERGY DEPENDENCE
INELASTIC SCATTERING
INTERFACES
KEV RANGE
LAYERS
MONTE CARLO METHOD
NICKEL
NICKEL OXIDES
PHOTONS
SENSITIVITY
SURFACES
THIN FILMS
VARIATIONS
X RADIATION
X-RAY SPECTRA
X-RAY SPECTROSCOPY
YIELDS