title: Oxygen nonstoichiometry, defect structure and oxygen diffusion in the double perovskite GdBaCo2O6-δ.
abstract: Oxygen nonstoichiometry of GdBaCo2O6-δ was studied by means of the thermogravimetric technique in the temperature range 600-1000 °C. The defect structure model based on the simple cubic perovskite GdCoO3-δ was shown to be valid for GdBaCo2O6-δ up to temperatures as low as 600 °C. Two independent methods, namely dc-polarization with the YSZ microelectrode and (18)O-isotope exchange with gas phase analysis, were used to determine the oxygen self-diffusion coefficient in the double perovskite GdBaCo2O6-δ. All measurements were carried out using ceramic samples identically prepared from the same single phase powder of GdBaCo2O6-δ. The experimental data on oxygen nonstoichiometry of GdBaCo2O6-δ allowed a precise calculation of the oxygen interphase exchange rate and the oxygen tracer diffusion coefficient on the basis of the isotope exchange measurements. The values of the oxygen self-diffusion coefficient measured by the dc-polarization technique were found to be in very good agreement with the ones of the oxygen tracer diffusion coefficient.
authors.affiliation: Department of Chemistry, Institute of Natural Sciences, Ural Federal University, Ekaterinburg, 620000, Russia. dmitry.tsvetkov@urfu.ru.
authors.forename: D S
authors.initials: DS
authors.lastname: Tsvetkov
authors.forename: M V
authors.initials: MV
authors.lastname: Ananjev
authors.forename: V A
authors.initials: VA
authors.lastname: Eremin
authors.forename: A Yu
authors.initials: AY
authors.lastname: Zuev
authors.forename: E Kh
authors.initials: EKh
authors.lastname: Kurumchin