TY - JOUR

T1 - Methods of isotopic relaxations for estimation of oxygen diffusion coefficients in solid electrolytes and materials with mixed ionic-electronic conductivity

AU - Sadykov, V. A.

AU - Sadovskaya, E. M.

AU - Uvarov, N. F.

PY - 2015/5/1

Y1 - 2015/5/1

N2 - Theoretical basis of isotopic oxygen exchange in a gas-solid oxide system are considered. A generalized model is suggested that accounts for diffusion of tracer oxygen atoms and allows within a single approach to perform numeric analysis of isotope experiments implemented in reactors of various types and in different temperature modes. It is shown that when C18O2 is used as an isotopic reagent, the oxygen exchange rate on the metal oxide surface increases manifold (as compared to 18O2), which allows determining more precisely diffusion limitations in case of isotopic exchange of oxygen in the oxide bulk. Estimates of oxygen self-diffusion coefficients are obtained in dispersed systems based on doped cerium-zirconium oxides with a fluorite-type structure, doped lanthanum silicates with an apatite-type structure, and also mixed praseodymium nickelates-cobaltites and their composites with yttrium-doped ceria.

AB - Theoretical basis of isotopic oxygen exchange in a gas-solid oxide system are considered. A generalized model is suggested that accounts for diffusion of tracer oxygen atoms and allows within a single approach to perform numeric analysis of isotope experiments implemented in reactors of various types and in different temperature modes. It is shown that when C18O2 is used as an isotopic reagent, the oxygen exchange rate on the metal oxide surface increases manifold (as compared to 18O2), which allows determining more precisely diffusion limitations in case of isotopic exchange of oxygen in the oxide bulk. Estimates of oxygen self-diffusion coefficients are obtained in dispersed systems based on doped cerium-zirconium oxides with a fluorite-type structure, doped lanthanum silicates with an apatite-type structure, and also mixed praseodymium nickelates-cobaltites and their composites with yttrium-doped ceria.

KW - composites

KW - doped cerium-zirconium oxides

KW - doped lanthanum silicates

KW - isotopic exchange of oxygen

KW - mixed praseodymium nickelates-cobaltites

KW - self-diffusion

UR - http://www.scopus.com/inward/record.url?scp=84930204878&partnerID=8YFLogxK

U2 - 10.1134/S1023193515050109

DO - 10.1134/S1023193515050109

M3 - Article

AN - SCOPUS:84930204878

VL - 51

SP - 458

EP - 467

JO - Russian Journal of Electrochemistry

JF - Russian Journal of Electrochemistry

SN - 1023-1935

IS - 5

ER -