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AuthorBergbreiter, Andreasdc.contributor.author
Date of accession2016-03-15T06:23:52Zdc.date.accessioned
Available in OPARU since2016-03-15T06:23:52Zdc.date.available
Year of creation2011dc.date.created
AbstractIn this work, various bimetallic model surfaces were prepared on Ru(0001) and Pt(111) single crystals and structurally characterized by scanning tunneling microscopy (STM) and Auger-electron spectroscopy (AES) to identify the atomic structures of surface confined alloys, their stabilities and the surface alloy formation process. Furthermore, Monte-Carlo (MC) simulations based on a 2D lattice-gas Hamiltonian (limited to effective pair interactions) provide an adequate energetic description of the surface alloy structures and allow for correlations with density functional theory calculations. The preparation of metastable lateral equilibrated alloys confined to the outermost layer and their characterization with respect to the atom arrangement was successfully performed for the bimetallic systems PtRu/Ru(0001), PdRu/Ru(0001) and AuPt/Pt(111), covering many different compositions in the range of 0 < x < 1 for each system. The MC simulations based on experiment - CuPd/Ru(0001), PtRu/Ru(0001), PdRu /Ru(0001), AuPt /Pt(111) - and DFT energies - AuPt/Pt(111) - reproduce the experimentally found ensemble and ligand statistics with excellent agreement. This structural information could be in several cases correlated with (electro-)catalytic properties of the respective surface alloy. Stability aspects and the surface alloy formation process was studied via various overgrowth experiments - PdRu, PtRu - and the "freezing" of the surface structure after initial metal-metal exchange processes - PtRu/Ru(0001). Based on these experiments a surface alloy formation mechanism is suggested and the relative strong stability towards surface confinement confirmed. The formation of metastable binary surface alloys can be generally predicted by comparing the nearest-neighbour bulk distances and the surface energy of both components.dc.description.abstract
Languageendc.language.iso
PublisherUniversität Ulmdc.publisher
LicenseStandard (Fassung vom 01.10.2008)dc.rights
Link to license texthttps://oparu.uni-ulm.de/xmlui/license_v2dc.rights.uri
KeywordEffective pair interactiondc.subject
KeywordEnsemble statisticsdc.subject
KeywordLattice gas Hamiltoniandc.subject
KeywordLigand statisticsdc.subject
KeywordShort-range orderdc.subject
KeywordSingle crystaldc.subject
KeywordSurface alloydc.subject
KeywordUltra-high vacuumdc.subject
Dewey Decimal GroupDDC 540 / Chemistry & allied sciencesdc.subject.ddc
LCSHAuger electron spectroscopydc.subject.lcsh
LCSHCopperdc.subject.lcsh
LCSHPhase diagramsdc.subject.lcsh
LCSHPlatinumdc.subject.lcsh
LCSHScanning tunneling microscopydc.subject.lcsh
LCSHRutheniumdc.subject.lcsh
TitleAtomic structure, stability and formation of surface confined alloysdc.title
Resource typeDissertationdc.type
DOIhttp://dx.doi.org/10.18725/OPARU-1911dc.identifier.doi
PPN662449223dc.identifier.ppn
URNhttp://nbn-resolving.de/urn:nbn:de:bsz:289-vts-76482dc.identifier.urn
GNDGolddc.subject.gnd
GNDMonte-Carlo-Simulationdc.subject.gnd
GNDPalladiumdc.subject.gnd
GNDRutheniumdc.subject.gnd
FacultyFakultät für Naturwissenschaftenuulm.affiliationGeneral
Date of activation2011-06-14T15:07:07Zuulm.freischaltungVTS
Peer reviewneinuulm.peerReview
Shelfmark print versionZ: J-H 14.079; W: W-H 12.542uulm.shelfmark
DCMI TypeTextuulm.typeDCMI
VTS-ID7648uulm.vtsID
CategoryPublikationenuulm.category
University Bibliographyjauulm.unibibliographie


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