Defect chemistry and surface oxygen exchange kinetics of La-doped Sr(Ti,Fe)O3 - α in oxygen-rich atmospheres

Nicola Helen Perry, Daniele Pergolesi, Sean R. Bishop, Harry L. Tuller

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

Abstract The mixed ionic and electronic conductor Sr(Ti,Fe)O3-α (STF) exhibits fast oxygen surface exchange kinetics, with electron concentration potentially playing a key role. The effect of La donor doping on electron concentration, Fermi level, and overall defect chemistry of STF is investigated on Sr1-yLayTi0.65Fe0.35O3-α (LSTF, 0 ≤ y ≤ 0.5) thin films. Defect chemical modeling, optical absorption, and electrical conductivity measurements in oxidizing conditions indicate compensation of donors by an increase in oxygen and electron concentrations, increase in Fermi level, decrease in oxygen vacancy and hole concentrations, and formation of cation vacancies (for [La] > [Fe]). The surface exchange coefficient, measured by impedance spectroscopy, decreased with increasing donor concentration, suggesting that oxygen exchange kinetics in LSTF are limited by low oxygen vacancy and/or hole concentrations, rather than electron transfer.

Original languageEnglish
Article number13457
Pages (from-to)18-24
Number of pages7
JournalSolid State Ionics
Volume273
DOIs
Publication statusPublished - May 1 2015

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chemistry
Oxygen
atmospheres
Hole concentration
Defects
Kinetics
Electrons
defects
kinetics
oxygen
Oxygen vacancies
Fermi level
Light absorption
Vacancies
Cations
electrons
Positive ions
Doping (additives)
Spectroscopy
Thin films

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics

Cite this

Defect chemistry and surface oxygen exchange kinetics of La-doped Sr(Ti,Fe)O3 - α in oxygen-rich atmospheres. / Perry, Nicola Helen; Pergolesi, Daniele; Bishop, Sean R.; Tuller, Harry L.

In: Solid State Ionics, Vol. 273, 13457, 01.05.2015, p. 18-24.

Research output: Contribution to journalArticle

Perry, Nicola Helen ; Pergolesi, Daniele ; Bishop, Sean R. ; Tuller, Harry L. / Defect chemistry and surface oxygen exchange kinetics of La-doped Sr(Ti,Fe)O3 - α in oxygen-rich atmospheres. In: Solid State Ionics. 2015 ; Vol. 273. pp. 18-24.
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