Thermoelectric properties of strontium titanate superlattices incorporating niobium oxide nanolayers

Handle URI:
http://hdl.handle.net/10754/563506
Title:
Thermoelectric properties of strontium titanate superlattices incorporating niobium oxide nanolayers
Authors:
Sarath Kumar, S. R.; Hedhili, Mohamed N. ( 0000-0002-3624-036X ) ; Cha, Dong Kyu; Tritt, Terry M.; Alshareef, Husam N. ( 0000-0001-5029-2142 )
Abstract:
A novel superlattice structure based on epitaxial nanoscale layers of NbOx and Nb-doped SrTiO3 is fabricated using a layer-by-layer approach on lattice matched LAO substrates. The absolute Seebeck coefficient and electrical conductivity of the [(NbOx) a/(Nb-doped SrTiO3)b]20 superlattices (SLs) were found to increase with decreasing layer thickness ratio (a/b ratio), reaching, at high temperatures, a power factor that is comparable to epitaxial Nb-doped SrTiO3 (STNO) films (∼0.7 W m-1 K-1). High temperature studies reveal that the SLs behave as n-type semiconductors and undergo an irreversible change at a varying crossover temperature that depends on the a/b ratio. By use of high resolution X-ray photoelectron spectroscopy and X-ray diffraction, the irreversible changes are identified to be due to a phase transformation from cubic NbO to orthorhombic Nb2O5, which limits the highest temperature of stable operation of the superlattice to 950 K. © 2014 American Chemical Society.
KAUST Department:
Materials Science and Engineering Program; Physical Sciences and Engineering (PSE) Division; Core Labs; Functional Nanomaterials and Devices Research Group
Publisher:
American Chemical Society (ACS)
Journal:
Chemistry of Materials
Issue Date:
22-Apr-2014
DOI:
10.1021/cm500646f
Type:
Article
ISSN:
08974756
Sponsors:
S.R.S.K., H.N.A., and T.M.T. acknowledge the financial support of the KAUST Competitive Faculty-Initiated Collaboration Grant.
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Materials Science and Engineering Program

Full metadata record

DC FieldValue Language
dc.contributor.authorSarath Kumar, S. R.en
dc.contributor.authorHedhili, Mohamed N.en
dc.contributor.authorCha, Dong Kyuen
dc.contributor.authorTritt, Terry M.en
dc.contributor.authorAlshareef, Husam N.en
dc.date.accessioned2015-08-03T11:53:08Zen
dc.date.available2015-08-03T11:53:08Zen
dc.date.issued2014-04-22en
dc.identifier.issn08974756en
dc.identifier.doi10.1021/cm500646fen
dc.identifier.urihttp://hdl.handle.net/10754/563506en
dc.description.abstractA novel superlattice structure based on epitaxial nanoscale layers of NbOx and Nb-doped SrTiO3 is fabricated using a layer-by-layer approach on lattice matched LAO substrates. The absolute Seebeck coefficient and electrical conductivity of the [(NbOx) a/(Nb-doped SrTiO3)b]20 superlattices (SLs) were found to increase with decreasing layer thickness ratio (a/b ratio), reaching, at high temperatures, a power factor that is comparable to epitaxial Nb-doped SrTiO3 (STNO) films (∼0.7 W m-1 K-1). High temperature studies reveal that the SLs behave as n-type semiconductors and undergo an irreversible change at a varying crossover temperature that depends on the a/b ratio. By use of high resolution X-ray photoelectron spectroscopy and X-ray diffraction, the irreversible changes are identified to be due to a phase transformation from cubic NbO to orthorhombic Nb2O5, which limits the highest temperature of stable operation of the superlattice to 950 K. © 2014 American Chemical Society.en
dc.description.sponsorshipS.R.S.K., H.N.A., and T.M.T. acknowledge the financial support of the KAUST Competitive Faculty-Initiated Collaboration Grant.en
dc.publisherAmerican Chemical Society (ACS)en
dc.titleThermoelectric properties of strontium titanate superlattices incorporating niobium oxide nanolayersen
dc.typeArticleen
dc.contributor.departmentMaterials Science and Engineering Programen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentCore Labsen
dc.contributor.departmentFunctional Nanomaterials and Devices Research Groupen
dc.identifier.journalChemistry of Materialsen
dc.contributor.institutionDepartment of Physics and Astronomy, Clemson University, SC 29634, United Statesen
kaust.authorHedhili, Mohamed N.en
kaust.authorCha, Dong Kyuen
kaust.authorAlshareef, Husam N.en
kaust.authorSarath Kumar, S. R.en
All Items in KAUST are protected by copyright, with all rights reserved, unless otherwise indicated.