Oxygen nonstoichiometry, defect structure and oxygen diffusion in the double perovskite GdBaCo2O6-d

Dalton transactions (Cambridge, England : 2003)

PubMedID: 25231733

Tsvetkov DS, Ananjev MV, Eremin VA, Zuev AY, Kurumchin EK. Oxygen nonstoichiometry, defect structure and oxygen diffusion in the double perovskite GdBaCo2O6-d. Dalton Trans. 2014;.
Oxygen nonstoichiometry of GdBaCo2O6-d 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-d was shown to be valid for GdBaCo2O6-d 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-d. All measurements were carried out using ceramic samples identically prepared from the same single phase powder of GdBaCo2O6-d. The experimental data on oxygen nonstoichiometry of GdBaCo2O6-d 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.