Electrical conductivity and defect disorder of tantalum-doped TiO2

Mohammad A. Alim, Tadeusz Bak, Armand Atanacio, Johan Du Plessis, Meifang Zhou, Joel Davis, Janusz Nowotny

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)

Abstract

The present work reports the electrical properties of polycrystalline Ta-doped TiO2 (0.39 at.% Ta) determined in situ at elevated temperatures (1173-1323 K) in the gas phase of controlled oxygen activity (10-12 Pa to 105 Pa). The effect of oxygen activity on the electrical conductivity and thermoelectric power of TiO2 is discussed in terms of defect disorder, including (1) the intrinsic electronic disorder that is governed by electronic compensation in the strongly reducing regime, (2) the extrinsic electronic disorder that is governed by electronic charge compensation in the reducing regime, and (3) the extrinsic ionic disorder that is governed by ionic compensation in the oxidizing regime. It is shown that tantalum ions are incorporated into the titanium sublattice of TiO2 leading to the formation of donor-type energy levels. The Arrhenius-type plot of the electrical conductivity data leads to the determination of the formation enthalpy terms. The obtained results are considered in terms of the effect of tantalum and oxygen activity on the defect disorder and the associated key performance-related properties in the light-induced partial water oxidation.
Original languageEnglish
Pages (from-to)4088-4100
Number of pages13
JournalJournal of the American Ceramic Society
Volume100
Issue number9
Publication statusPublished - Sept 2017

Bibliographical note

Publisher Copyright:
© 2017 The American Ceramic Society

Keywords

  • defects
  • electric conductivity
  • electric properties
  • oxides
  • oxygen
  • titanium dioxide

Fingerprint

Dive into the research topics of 'Electrical conductivity and defect disorder of tantalum-doped TiO2'. Together they form a unique fingerprint.

Cite this