Location of Repository

The all-electron density functional theory (DFT) code Wien2k has an established track record of modelling energy-loss near-edge structure (ELNES). The pseudopotential DFT code CASTEP can reproduce results found using Wien2k. A methodology was developed for DFT code parameter selection,\ud based on converging parameters to the ELNES prediction. Various aluminium systems were studied; aluminium, aluminium nitride and aluminium oxide. Uniquely for aluminium metal, a ground state calculation provided strong\ud agreement with experiment, as the core-hole is well screened. It was quantitatively demonstrated that the core-hole causes ionisation edge peaks to shift towards the Fermi level, and increases the intensity of those peaks -\ud effects found to be larger for the cationic species. Group 4 and 5 transition metal carbides were modelled using CASTEP. Systems with vacancies were considered; TiC0.79, TiC0.58N0.30, TiC0.45N0.43, TiC0.19N0.65 and TiN0.82. By\ud comparison with experimental data, structures for these systems were proposed. CASTEP was used to model oxygen K edges in various systems. For bulk MgO, acceptable experimental agreement was found using a ground state\ud calculation. This was rationalised by observing that the introduction of a corehole had relatively little effect on the p orbital DOS prediction for oxygen. For the interface of Fe (001) / MgO (001), it was demonstrated by careful\ud comparison of theory and experiment that some degree of oxidation was present. Nanoscale analysis of multilayered CrAlYN/CrN coatings was performed. Experimentally observed ELNES was reproduced using ground state Wien2k calculations. Combined experimental and theoretical analysis\ud indicated that the nominal CrN layers were close to stoichiometric CrN, the Cr/N ratio being 1.05 ± 0.1. For the CrAlYN layers, the theoretical system showing the best agreement was Cr0.5Al0.5N. This thesis has established methodologies for utilising DFT codes, illustrating how links between experimental and theoretical ELNES can be used in the nanoscale characterisation of technologically important materials

Publisher: School of Chemical and Process Engineering (Leeds)

Year: 2010

OAI identifier:
oai:etheses.whiterose.ac.uk:1447

Provided by:
White Rose E-theses Online

Downloaded from
http://etheses.whiterose.ac.uk/1447/2/phd_thesis_seabourne.pdf

- (2007). 11.2 Prizes and awards won during PhD studies 1
- (2009). 11.3 Conferences and funding during PhD studies 1
- (2001). A Chemists’ Guide to Density Functional Theory.
- (2007). A history of scanning electron microscopy developments: Towards "wet-STEM" imaging.
- (1992). A new method for hard coatings: ABSTM (arc bond sputtering).
- (2005). A program for the calculation of Energy Loss Near Edge Structure. The new and improved TELNES.2 Code,
- (2009). A systematic approach to choosing parameters for modelling fine structure in electron energy-loss spectroscopy.
- (2001). A theorem on high-order geometric spherical aberrations for Hutter's electrostatic lens.
- (2008). A theoretical study of ELNES spectra of AlxGa1-xN using Wien2k and Telnes programs.
- (1971). A Wien Filter for Use as an Energy Analyzer with an Electron Microscope.
- (2010). Ab initio calculation of the energy-loss near-edge structure of some carbon allotropes: Comparison with ndiamond.
- (1986). Aberrations of Optical Systems: (The Adam Hilger Series On Optics & Optoelectronics).
- (1986). Accurate and simple density functional for the electronic exchange energy: Generalized gradient approximation.
- (1996). Adlayer core-level shifts of admetal monolayers on transition-metal substrates and their relation to the surface chemical reactivity.
- (2008). An Introduction to Highresolution
- (2009). an oral presentation which was well received.
- (2010). Analysis of computational EELS modelling results for MgO-based systems.
- (2003). Anisotropy and collection angle dependence of the oxygen K ELNES in V2O5: a band-structure calculation study.
- (2006). Atom probe field ion microscope measurements of carbon segregation at an a:a grain boundary and service failures by intergranular stress corrosion cracking.
- (1993). Atomic resolution with an atomic force microscope using piezoresistive detection.
- (2003). Bandstructure approach to near edge structure.
- (1970). Charge-coupled semiconductor devices.
- (1998). Connections between the electronenergy-loss spectra, the local electronic structure, and the physical properties of a material: A study of nickel aluminum alloys.
- (2008). Core Level Spectroscopy of Solids.
- (2009). Core-hole effect in the one-particle approximation revisited from density functional theory.
- (2009). Core-hole effect in the one-particle approximation revisited from Density Functional Theory. EDGE Conference (Banff), private communication.
- (2001). Core-hole effects on energy-loss near-edge structure.
- (2000). Core-hole effects on theoretical electron-energy-loss near-edge structure and near-edge x-ray absorption fine structure of MgO.
- (2006). CrAlYN/CrN superlattice coatings deposited by the combined high power impulse magnetron sputtering/unbalanced magnetron sputtering technique.
- (2001). Cubic boron nitride: Experimental and theoretical energy-loss near-edge structure.
- (2008). Decisive factors for realizing atomiccolumn resolution using STEM and EELS.
- (2004). Design of Wien filters with high resolution.
- (1999). Development of a high energy resolution electron energy-loss spectroscopy microscope.
- (2005). Diffraction Grating Handbook, 6th edn.
- (2000). Digital imaging in transmission electron microscopy.
- (2010). EELS and ELNES studies of nano-scale nitride multilayers deposited by unbalanced magnetron sputtering.
- (1990). EELS elemental mapping with unconventional methods II. Applications to biological specimens.
- (2003). EELS performance measurements on a new high energy resolution imaging filter.
- (1999). Effect of interlayer composition on the tribological properties of TiC/Ti(Cx, N1−x)/TiN anti-abrasive multi-layer coatings.
- (1995). Electric field gradients, isomer shifts and hyperfine fields from band structure calculations in
- (1995). Electron Energy Loss Near Edge Structure (ELNES) on the Carbon K-Edge in Transition Metal Carbides with the Rock Salt Structure.
- (2001). Electron Energy Loss Spectroscopy. Bios Scientific Publishers,
- (2004). Electron energy loss-near edge structure as a fingerprint for identifying chromium nitrides.
- (2006). Electron energy-loss spectra calculations and experiments as a tool for the identification of a lamellar C3N4 compound.
- (1996). Electron Energy-Loss Spectroscopy in the Electron Microscope, 2nd edn.
- (2009). Electron energy-loss spectroscopy in the TEM.
- (2006). Electron spectroscopy of carbon materials: experiment and theory.
- (1993). Electron-energy-loss nearedge structures in the oxygen K-edge spectra of transition-metal oxides.
- (1991). Electron-energy-loss-spectroscopy nearedge fine structures in the iron-oxygen system.
- (1998). Electronic band structure in hexagonal closepacked Si polytypes.
- (1998). Electronic band structures of the scheelite materials
- (2002). Electronic structure and energetics of ordered titanium carbides of composition Ti2C.
- (1997). Electronic structure and structural stability of TiCxN1-x alloys.
- (2002). Electronic structure calculations of solids using the WIEN2k package for material sciences.
- (2004). Electronic Structure: Basic Theory and Practical Methods.
- (2008). Energy-loss near-edge structure (ELNES) and first-principles calculation of electronic structure of nickel silicide systems.
- (2009). Enhanced Data Generated by Electrons (EDGE) conference,
- (2008). Epitaxial growth of cubic AlN films on SrTiO3 (100) substrates by pulsed laser deposition.
- (2008). European Microscopy Congress, Aachen. • Presented a successful poster, and obtained several useful contacts.
- (2000). Excitonic Effects in Core-Excitation Spectra of Semiconductors.
- (2001). Exponential Decay Properties of Wannier Functions and Related Quantities.
- (1997). First principles calculations of the electronic structure and spectra of strongly correlated systems:
- (2002). First principles methods using CASTEP.
- (1997). First-principles band-structure calculations as a tool for the quantitative interpretation of Raman spectra of high temperature superconductors.
- (2009). First-principles calculation of spectral features, chemical shift and absolute threshold of ELNES and XANES using a plane wave pseudopotential method.
- (2009). First-principles calculations of x-ray absorption near edge structure and energy loss near edge structure: present and future
- (1996). Force calculation and atomic-structure optimization for the full-potential linearized augmented plane-wave code WIEN.
- (1990). Full-potential, linearized augmented plane wave programs for crystalline systems.
- (1946). Further improvement in the resolving power of the electron microscope.
- (2005). High Spatial and Energy Resolution EELS using a Monochromated STEM.
- (1992). High-Order Multiple-Scattering Calculations of X-Ray Absorption Fine Structure.
- (2003). Image states and excitons at insulator surfaces with negative electron affinity.
- (2003). Improvement of energy loss near edge structure calculation using Wien2k.
- (2008). In situ synchrotron studies of ZnO nanostructures during electrochemical deposition.
- (2001). Industrial scale manufactured superlattice hard PVD coatings.
- (2005). Influence of nitrogen vacancies on the N K-ELNES spectrim of titanium nitride.
- (1986). Influence of the ordering of carbon vacancies on the electronic properties of TiC0.625.
- (2007). Initial results from the first monochromated FEI Titan 80/300 in the UK.
- (2009). Institute of Materials, Minerals and Mining award. • Award of £100 for winning the Leeds Bradford Materials Society Young Persons’ Lecture contest.
- (2009). Institute of Materials, Minerals and Mining Literature Review Competition. • Reached the final six in the competition. • Attended a masterclass in London on scientific writing.
- (2009). Institute of Physics grant.
- (2007). Interface microstructure engineering by high power impulse magnetron sputtering for the enhancement of adhesion.
- (1997). Intermediate quantum mechanics.
- (2002). Intrinsic electronic structure of threading dislocations in GaN.
- (2005). Introducing ONETEP: Linear-scaling density functional simulations on parallel computers.
- (2006). Introduction to Optics, 3rd edn.
- (2004). Investigation of hexagonal and cubic GaN by high-resolution electron energy-loss spectroscopy and density functional theory.
- (1992). Iterative minimization techniques for ab initio total-energy calculations: molecular dynamics and conjugate gradients.
- (1990). Modern Optics.
- (2009). Modification of optical properties of MgO thin films by vapour chopping.
- (1989). Multiple-scattering approach to oxygen K near-edge structures in electron-energy-loss spectroscopy of alkaline earths.
- (2005). Multiplet effects in X-ray spectroscopy.
- (2007). Multivariate Statistical Analysis of EFTEM data.
- (2008). N-K electron energy-loss near-edge structures for TiN/VN layers: an ab initio and experimental study.
- (2010). Nano-scale electron energy loss spectroscopy of CrAlYN/CrN – CrAlY(O)N/Cr(O)N multilayer coatings deposited by unbalanced magnetron sputtering.
- (2007). Nanomaterials and nanoparticles: Sources and toxicity.
- (2007). National Grid Service computing resource allocation. • Awarded 5000 (increased to over 400,000) hours of computing time on the National Grid Service network.
- (1979). Natural widths of atomic K and L levels, Kα Xray lines and several KLL Auger lines.
- (1986). Near-edge structure in electron-energy-loss spectra of MgO.
- (2008). Near-simultaneous dual energy range EELS spectrum imaging.
- (2002). Neutron diffraction study of the ordered structures of nonstoichiometric titanium carbide.
- (2008). of over £200 obtained to assist with presentation of research at the European Microscopy Congress,
- (1943). On Microanalysis by Electrons.
- (2006). ONETEP: linearscaling density-functional theory with local orbitals and plane waves.
- (2006). ONETEP: linearscaling density-functional theory with plane-waves.
- (2000). Opportunities and pitfalls in characterisation of nanoscale features.
- (1985). Order and disorder in transition metal carbides and nitrides: experimental and theoretical aspects.
- (2009). Overlap population diagram for ELNES and XANES: peak assignment and interpretation.
- (2004). Oxidation behaviour of nanoscale TiAlN/VN multilayer coatings.
- (2006). Oxidation resistant coatings in combination with thermal barrier coatings on γ-TiAl alloys for high temperature applications.
- (2006). Peak assignments of ELNES and XANES using overlap population diagrams.
- (2006). Perfection in Theoretical Modeling of Electron Energy Loss Spectra: Is it attainable?
- (2005). Performance of nanostructured multilayer PVD coating TiAlN/VN in dry high speed milling of aerospace aluminium 7010-T7651.
- (1998). Performance of oxygen-rich TiALON coatings in dry cutting applications.
- (2008). Practical approaches to the accurate modelling of EELS edges using density functional theory.
- (2010). Probing magnetic order in EELS of chromite spinels using both multiple scattering (FEFF8.2) and DFT (WIEN2k).
- (2001). Progress in aberration-corrected scanning transmission electron microscopy.
- (2003). PVD–IBAD zinc coating development for automotive application.
- (1979). Quantitative electron spectroscopy of surfaces: A standard data base for electron inelastic mean free paths in solids.
- (1998). Real Space Multiple Scattering Calculation of XANES.
- (2009). Realising the potential’ conference in Electron Microscopy, Imperial College London. • Major topics – EELS, imaging techniques and modelling.
- (2005). Relativistic cluster calculation of ligand-field multiplet effects on cation L2,3 X-ray absorption edges of SrTiO3, NiO,
- (1997). Relaxation of Crystals with the Quasi-Newton Method.
- (1994). Scanning electron microscopy of the fourth antennular segement of Balanus amphitrite amphitrite.
- (2005). Scanning transmission electron microscopy and its application to the study of nanoparticles and nanoparticle systems.
- (2006). Second-order aberration corrected electron energy loss spectroscopy attachment for scanning electron microscopes.
- (1965). Self-Consistent Equations Including Exchange and Correlation Effects.
- (2005). Solid State Chemistry: An Introduction.
- (1960). Some Recent Advances in Density Matrix Theory.
- (2003). Some thoughts on source monochromation and the implications for electron energy loss spectroscopy.
- (1976). Special points for Brillouin-zone integrations.
- (2001). Spindependent tunneling conductance of Fe|MgO|Fe sandwiches.
- (2004). SpinPolarized Resonant Tunneling in Magnetic Tunnel Junctions.
- (2005). Structural, mechanical and tribological properties of CrAlN coatings deposited by reactive unbalanced magnetron sputtering.
- (2009). Structure and bonding at the atomic scale by scanning transmission electron microscopy.
- (2008). Studying Atomic Structures by Aberration-Corrected Transmission Electron Microscopy.
- (2002). Sub-ångstrom resolution using aberration corrected electron optics.
- (2001). Success and limits of common final-state approximations.
- (2002). Surface x-ray diffraction analysis of the MgO/Fe(001) interface: Evidence for an FeO layer.
- (2009). TEM and EELS measurements of interface roughness in epitaxial Fe/MgO/Fe magnetic tunnel junctions.
- (2007). TEM investigation of TiAlN/CrN multilayer coatings prepared by magnetron sputtering.
- (2008). Temperature dependence of giant tunnel magnetoresistance in epitaxial Fe/MgO/Fe magnetic tunnel junctions.
- (1970). The atom-probe field ion microscope.
- (2000). The nearedge structure in energy-loss spectroscopy: many-electron and magnetic effects in transition metal nitrides and carbides.
- (1996). The optimized effective potential for atoms and semiconductors.
- (1943). The origin of fringes about particles in electron microscope images and their change with focus. Kolloid Zeits.
- (2004). The properties and performance of Crbased multilayer nitride hard coatings using unbalanced magnetron sputtering and elemental metal targets.
- (1967). The Refractory Carbides.
- (2003). The study of Al-L23 ELNES with resolution-enhancement software and first-principles calculation.
- (2008). The Theory and Interpretation of Electron Energy Loss Near-Edge Fine Structure.
- (2005). Theoretical electron energy-loss spectroscopy and its application in materials research.
- (2001). Theoretical investigation of the ELNES of transition metal carbides for the extraction of structural and bonding information.
- (2008). Theory of core-hole effects in 1s core-level spectroscopy of the first-row elements.
- (1980). Theory of nonuniform electronic systems. I. Analysis of the gradient approximation and a generalization that works.
- (2000). Theory of solid state contributions to the x-ray elastic scattering amplitude.
- (1983). Theory of the X-Ray Absorption Near Edge Structure (XANES) at a Deep L2,3 Edge Studied by the Short-Range Order Multiple Scattering Theory.
- (1978). Thermal Conductivities, Electrical Resistivities, and Thermal Expansion of Titanium Carbonitrides and Oxycarbides.
- (2005). TiAlN based nanoscale multilayer coatings designed to adapt their tribological properties at elevated temperatures. Thin Solid Films 485,
- (2006). TiAlN/VN superlattice structured PVD coatings: A new alternative in machining of aluminium alloys for aerospace and automotive components.
- (2010). Towards the calculation of experimental spectra using O(N) DFT. ONETEP Workshop (Cambridge), private communication.
- (1990). Transition-metal oxides in the self-interactioncorrected density functional formulism.
- Transmission Electron Microscopy Study of the Fe(001) MgO(001) Interface for Magnetic Tunnel Junctions.
- (1996). Tungsten-Point-Cathode Electron Gun Using Electron Bombardment for Cathode Tip Heating: Cathode Life and Operating Characteristics at Cathode Temperatures above 2,800K.
- (1936). Über einige Fehler von Elektronenlinsen (About some of the errors in electron-lenses).
- (1992). Unoccupied Electronic States.
- (2003). Vacancy hardening in single-crystal TiNx(001) layers.
- (1997). Why the Generalized Gradient Approximation Works and How to Go Beyond It.
- (2006). X-ray absorption spectroscopic study of a hot pressed MgB2. Solid State Commun.
- (2009). XANES spectra of transition metal compounds.

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.