Molecular dynamics study of the thermopower of Ag, Au, and Pt nanocontacts

Using molecular dynamics simulations of many junction stretching processes combined with tight-binding-based electronic structure and transport calculations, we analyze the thermopower of silver (Ag), gold (Au), and platinum (Pt) atomic contacts. In all cases we observe that the thermopower vanishes on average within the standard deviation and that its fluctuations increase for a decreasing minimum cross section of the junctions. However, we find a suppression of the fluctuations of the thermopower for the s-valent metals Ag and Au, when the conductance originates from a single, perfectly transmitting channel. Essential features of the experimental results for Au, Ag, and copper (Cu) of Ludoph and van Ruitenbeek [ Phys. Rev. B 59 12290 (1999)], as yet unaddressed by atomistic studies, can hence be explained by considering the atomic and electronic structure at the disordered narrowest constriction of the contacts. For the multivalent metal Pt our calculations predict the fluctuations of the thermopower to be larger by one order of magnitude as compared to Ag and Au, and suppressions of the fluctuations as a function of the conductance are absent. Main features of our results are explained in terms of an extended single-level model.

Fachgebiet (DDC)

530 Physik

Zitieren

ISO 690

PAULY, Fabian, Janne K. VILJAS, Marius BÜRKLE, Michael DREHER, Peter NIELABA, Juan Carlos CUEVAS, 2011. Molecular dynamics study of the thermopower of Ag, Au, and Pt nanocontacts. In: Physical Review B. 2011, 84(19), 195420. ISSN 1098-0121. eISSN 1550-235X. Available under: doi: 10.1103/PhysRevB.84.195420

BibTex

@article{Pauly2011Molec-19166,
  year={2011},
  doi={10.1103/PhysRevB.84.195420},
  title={Molecular dynamics study of the thermopower of Ag, Au, and Pt nanocontacts},
  number={19},
  volume={84},
  issn={1098-0121},
  journal={Physical Review B},
  author={Pauly, Fabian and Viljas, Janne K. and Bürkle, Marius and Dreher, Michael and Nielaba, Peter and Cuevas, Juan Carlos},
  note={Article Number: 195420}
}

RDF

<rdf:RDF
    xmlns:dcterms="http://purl.org/dc/terms/"
    xmlns:dc="http://purl.org/dc/elements/1.1/"
    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
    xmlns:bibo="http://purl.org/ontology/bibo/"
    xmlns:dspace="http://digital-repositories.org/ontologies/dspace/0.1.0#"
    xmlns:foaf="http://xmlns.com/foaf/0.1/"
    xmlns:void="http://rdfs.org/ns/void#"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema#" > 
  <rdf:Description rdf:about="https://kops.uni-konstanz.de/server/rdf/resource/123456789/19166">
    <foaf:homepage rdf:resource="http://localhost:8080/"/>
    <dcterms:abstract xml:lang="eng">Using molecular dynamics simulations of many junction stretching processes combined with tight-binding-based electronic structure and transport calculations, we analyze the thermopower of silver (Ag), gold (Au), and platinum (Pt) atomic contacts. In all cases we observe that the thermopower vanishes on average within the standard deviation and that its fluctuations increase for a decreasing minimum cross section of the junctions. However, we find a suppression of the fluctuations of the thermopower for the s-valent metals Ag and Au, when the conductance originates from a single, perfectly transmitting channel. Essential features of the experimental results for Au, Ag, and copper (Cu) of Ludoph and van Ruitenbeek [ Phys. Rev. B 59 12290 (1999)], as yet unaddressed by atomistic studies, can hence be explained by considering the atomic and electronic structure at the disordered narrowest constriction of the contacts. For the multivalent metal Pt our calculations predict the fluctuations of the thermopower to be larger by one order of magnitude as compared to Ag and Au, and suppressions of the fluctuations as a function of the conductance are absent. Main features of our results are explained in terms of an extended single-level model.</dcterms:abstract>
    <dc:creator>Dreher, Michael</dc:creator>
    <dc:contributor>Nielaba, Peter</dc:contributor>
    <dc:contributor>Viljas, Janne K.</dc:contributor>
    <dc:date rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">2012-05-02T10:42:13Z</dc:date>
    <dcterms:hasPart rdf:resource="https://kops.uni-konstanz.de/bitstream/123456789/19166/2/pauly_191665.pdf"/>
    <dcterms:available rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">2012-05-02T10:42:13Z</dcterms:available>
    <dspace:isPartOfCollection rdf:resource="https://kops.uni-konstanz.de/server/rdf/resource/123456789/39"/>
    <dc:creator>Viljas, Janne K.</dc:creator>
    <dspace:isPartOfCollection rdf:resource="https://kops.uni-konstanz.de/server/rdf/resource/123456789/41"/>
    <dc:contributor>Pauly, Fabian</dc:contributor>
    <dcterms:isPartOf rdf:resource="https://kops.uni-konstanz.de/server/rdf/resource/123456789/39"/>
    <dc:contributor>Dreher, Michael</dc:contributor>
    <dc:language>eng</dc:language>
    <dcterms:bibliographicCitation>Physical Review B ; 84 (2011), 19. - 195420</dcterms:bibliographicCitation>
    <void:sparqlEndpoint rdf:resource="http://localhost/fuseki/dspace/sparql"/>
    <dc:creator>Cuevas, Juan Carlos</dc:creator>
    <dcterms:title>Molecular dynamics study of the thermopower of Ag, Au, and Pt nanocontacts</dcterms:title>
    <dc:contributor>Bürkle, Marius</dc:contributor>
    <dcterms:issued>2011</dcterms:issued>
    <dc:creator>Nielaba, Peter</dc:creator>
    <dcterms:isPartOf rdf:resource="https://kops.uni-konstanz.de/server/rdf/resource/123456789/41"/>
    <dspace:hasBitstream rdf:resource="https://kops.uni-konstanz.de/bitstream/123456789/19166/2/pauly_191665.pdf"/>
    <dc:contributor>Cuevas, Juan Carlos</dc:contributor>
    <dc:rights>terms-of-use</dc:rights>
    <dc:creator>Pauly, Fabian</dc:creator>
    <dc:creator>Bürkle, Marius</dc:creator>
    <bibo:uri rdf:resource="http://kops.uni-konstanz.de/handle/123456789/19166"/>
    <dcterms:rights rdf:resource="https://rightsstatements.org/page/InC/1.0/"/>
  </rdf:Description>
</rdf:RDF>

Universitätsbibliographie

Ja