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

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

Research output: Contribution to journalArticlepeer-review


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 (US)
Article number13457
Pages (from-to)18-24
Number of pages7
JournalSolid State Ionics
StatePublished - May 1 2015
Externally publishedYes


  • Defect chemistry
  • Electrical conductivity
  • Optical absorption
  • Oxygen surface exchange
  • SrTiO
  • Thin films

ASJC Scopus subject areas

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

Fingerprint Dive into the research topics of 'Defect chemistry and surface oxygen exchange kinetics of La-doped Sr(Ti,Fe)O<sub>3 - α</sub> in oxygen-rich atmospheres'. Together they form a unique fingerprint.

Cite this