Search results for "photoelectron spectra"

showing 3 items of 3 documents

Ab initio determination of the ionization potentials of DNA and RNA nucleobases

2006

Quantum chemical high level ab initio coupled-cluster and multiconfigurational perturbation methods have been used to compute vertical and adiabatic ionization potentials of the five canonical DNA and RNA nucleobases: uracil, thymine, cytosine, adenine, and guanine. Several states of their cations have been also calculated. The present results represent a systematic compendium of these magnitudes, establishing theoretical reference values at a level not reported before, calibrating computational strategies, and guiding the assignment of the features in the experimental photoelectron spectra. Daniel.Roca@uv.es Mercedes.Rubio@uv.es Manuela.Merchan@uv.es Luis.Serrano@uv.es

DNA ; Macromolecules ; Ionisation potential ; Photoelectron spectra ; Molecular biophysics ; Ab initio calculations ; Coupled cluster calculations ; Perturbation theoryGuanineGuaninePhotochemistryAb initioBiophysicsGeneral Physics and AstronomyIonisation potentialPerturbation theoryNucleobasechemistry.chemical_compoundCytosinePhotoelectron spectraCoupled cluster calculationsAb initio quantum chemistry methodsComputational chemistryIonizationPhysics::Atomic and Molecular ClustersPhysical and Theoretical ChemistryUracil:FÍSICA::Química física [UNESCO]IonsPhysics::Biological PhysicsQuantitative Biology::BiomoleculesBase CompositionChemistry PhysicalAdenineUracilDNAMolecular biophysicsQuantitative Biology::GenomicsThymineUNESCO::FÍSICA::Química físicachemistryMacromoleculesCalibrationQuantum TheoryRNAAb initio calculationsCytosineSoftwareThymine
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Thin film growth and band lineup of In2O3 on the layered semiconductor InSe

1999

Thin films of the transparent conducting oxide In2O3 have been prepared in ultrahigh vacuum by reactive evaporation of indium. X-ray diffraction, optical, and electrical measurements were used to characterize properties of films deposited on transparent insulating mica substrates under variation of the oxygen pressure. Photoelectron spectroscopy was used to investigate in situ the interface formation between In2O3 and the layered semiconductor InSe. For thick In2O3 films a work function of φ = 4.3 eV and a surface Fermi level position of EF−EV = 3.0 eV is determined, giving an ionization potential IP = 7.3 eV and an electron affinity χ = 3.7 eV. The interface exhibits a type I band alignmen…

Materials scienceAnalytical chemistryIonisation potentialGeneral Physics and AstronomyWork functionPhotoelectron spectrasymbols.namesakeX-ray photoelectron spectroscopyIndium compounds:FÍSICA [UNESCO]Electron affinityWork functionThin filmbusiness.industryFermi levelUNESCO::FÍSICAHeterojunctionInterface statesBand structureEvaporation (deposition)X-ray diffractionElectron affinitySemiconductorVacuum depositionIndium compounds ; Vacuum deposition ; X-ray diffraction ; Photoelectron spectra ; Semiconductor-insulator boundaries ; Work function ; Fermi level ; Ionisation potential ; Electron affinity ; Interface states ; Band structureFermi levelsymbolsSemiconductor-insulator boundariesOptoelectronicsbusiness
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Stoichiometry-related Auger lineshapes in titanium oxides: Influence of valence-band profile and of Coster-Kronig processes

2004

International audience; The ability to determine the nature and the occurrence of defects is a central need of ceramic surface chemistry. In titanium oxides, the Ti-LMV Auger decays line shape is very sensitive to the titanium degree of oxidation, and has long been empirically used as a qualitative probe of the stoichiometry. In the present work, resonant Auger and resonant valence-band measurements at the Ti-L2,3 edges in TiO2, TiO2–x and metallic titanium provide a clear evidence that the evolutions of the Ti-LMV Auger line shape are due to drastic changes in the valence-band profile and in the probability of L2L3V Coster-Kronig decay processes when a fraction of titanium ions is reduced.…

PACS: 71.20.-b 32.80.Hd 77.84.Bw 82.80.Pvoxidationchemistry.chemical_element02 engineering and technologyceramics01 natural sciencesElectron spectroscopy71.20.-b; 32.80.Hd; 77.84.Bw; 82.80.PvIonAugerX-RAY-ABSORPTION; SURFACE-DEFECTS; RUTILE TIO2; Resonant AugerMetalsymbols.namesakephotoelectron spectra0103 physical sciencesRUTILE TIO2titanium010306 general physicstitanium compoundsAuger electron spectroscopyFermi levelvalence bandsResonant Auger021001 nanoscience & nanotechnologyCondensed Matter PhysicsSURFACE-DEFECTSElectronic Optical and Magnetic Materialsstoichiometrychemistryvisual_artX-RAY-ABSORPTIONsymbolsvisual_art.visual_art_mediumFermi levelspectral line breadthAuger electron spectraAtomic physics0210 nano-technologyStoichiometryTitanium
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