Abstract

We report on low-temperature (4-320 K) transport properties of Ta xN thin films deposited on an amorphous SiO2 substrate. In this work, TaxN thin films were restricted to a narrow range of x: 0.72 ≤ x ≤ 0.83 yet show considerable and nonmonotonic variation of their transport properties with Ta concentration. This behaviour is consistent with a local minimum in the density of electronic states at the Fermi level, as calculated for the rock salt intermetallic Ta4N5, and a rigid band model for describing the transport. The temperature dependence of the resistivity is best fit to the unusual form exp(-T/T0). Interestingly enough, the fit parameter T0 correlates well with the temperature of the maximum of the corresponding thermopower. Both of these characteristics, the fit and the correlation with the thermopower, are consistent with the Jonson-Mahan many-body formalism for charge and thermal transport when one has a nontrivial temperature dependence of the chemical potential. At the lowest temperatures measured, we have also found that the resistivity and thermopower show signatures of electron-electron interactions. We discuss also our results in the light of some theories usually used for describing transport of thin films and to other experimental investigations that have been performed on Ta xN.

Original languageEnglish (US)
Article number445405
JournalJournal of Physics D: Applied Physics
Volume43
Issue number44
DOIs
StatePublished - Nov 10 2010

Fingerprint

Transport properties
transport properties
Thermoelectric power
Thin films
thin films
temperature dependence
electrical resistivity
halites
Temperature
intermetallics
electron scattering
Electron-electron interactions
signatures
Electronic density of states
formalism
Chemical potential
Fermi level
Intermetallics
electronics
Salts

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials
  • Acoustics and Ultrasonics
  • Surfaces, Coatings and Films

Cite this

Low-temperature transport properties of TaxN thin films (0.72 ≤ x ≤ 0.83). / Očko, Miroslav; Žonja, Sanja; Nelson, G. L.; Freericks, J. K.; Yu, Lei; Newman, Nathan.

In: Journal of Physics D: Applied Physics, Vol. 43, No. 44, 445405, 10.11.2010.

Research output: Contribution to journalArticle

Očko, Miroslav ; Žonja, Sanja ; Nelson, G. L. ; Freericks, J. K. ; Yu, Lei ; Newman, Nathan. / Low-temperature transport properties of TaxN thin films (0.72 ≤ x ≤ 0.83). In: Journal of Physics D: Applied Physics. 2010 ; Vol. 43, No. 44.
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