Theory of exchange reactions between fluids and solids with tracer diffusion in the solid

Klier, K.; Kučera, E.

doi:10.1016/0022-3697(66)90084-9

Cited by 64 publications

(25 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Steps 2-6 were repeated at different temperatures and oxygen pressures. Oxygen diffusion coefficient and surface exchange rate of the double perovskite GdBaCo 2 O 6-δ were calculated from the experimental data C i =f(t), where t is time and i denotes i-oxygen species ( 16 O 2 , 16 O 18 O, and 18 O 2 molecules), on the basis of the Klier and Kucera exchange kinetics model [15]. According to this model isotope diffusion in a solid phase which is in dynamic equilibrium with gas phase can be described, omitting the isotope effect, by the Fick's second law…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Oxygen nonstoichiometry, defect structure and oxygen diffusion in the double perovskite GdBaCo₂O_6−δ

et al. 2014

View full text Add to dashboard Cite

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.

show abstract

Section: Methodsmentioning

confidence: 99%

“…Solution of the Fick's equation derived by Klier and Kucera [15] with respect to the initial and boundary conditions gives the expression describing a time dependence of 18 O oxygen isotope fraction in the gas phase (13) and N g is a number of oxygen atoms in the gas phase. Terms Eq.…”

Section: Methodsmentioning

confidence: 99%

Oxygen nonstoichiometry, defect structure and oxygen diffusion in the double perovskite GdBaCo₂O_6−δ

et al. 2014

View full text Add to dashboard Cite

show abstract

“…To prevent limitation due to gas diffusion a circulation pump was used. The solution of tracer diffusion into the slab type geometry is given by [14] …”

mentioning

confidence: 99%

Oxygen tracer diffusion and surface exchange kinetics in Ba0.5Sr0.5Co0.8Fe0.2O3−δ

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Here, the most effective method is the SSITKA method of isotopic relaxations (Steady State Isotopic Transient Kinetic Analysis) [1][2][3]. As opposed to the known methods of analysis of relaxations of conductivity, mass, and spa tial profiles of oxygen isotopes in compact ceramics, analysis of relaxation of isotopic composition of the gaseous reagent in case of isotopic exchange with dis persed oxide oxygen allows determining not only aver age-integral diffusion coefficients of oxygen [4][5][6], but also detecting oxygen forms with different mobility in the solid oxide bulk [7][8][9]. This communication considers theoretical fundamentals of the dynamics of oxygen isotopic exchange in the gas-solid oxide sys tem, techniques of conducting isotopic experiments and methods of analysis of isotopic-kinetic data obtained in isothermic and temperature-pro grammed experiments in both flow-through and static setups.…”

Section: Introductionmentioning

confidence: 99%

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

2015

View full text Add to dashboard Cite

Theoretical basis of isotopic oxygen exchange in a gas-solid oxide system are considered. A gen eralized 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 C 18 O 2 is used as an isotopic reagent, the oxygen exchange rate on the metal oxide surface increases manifold (as compared to 18 O 2 ), 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.

show abstract

Theory of exchange reactions between fluids and solids with tracer diffusion in the solid

Cited by 64 publications

References 4 publications

Oxygen nonstoichiometry, defect structure and oxygen diffusion in the double perovskite GdBaCo₂O_6−δ

Oxygen nonstoichiometry, defect structure and oxygen diffusion in the double perovskite GdBaCo₂O_6−δ

Oxygen tracer diffusion and surface exchange kinetics in Ba0.5Sr0.5Co0.8Fe0.2O3−δ

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

Contact Info

Product

Resources

About

Theory of exchange reactions between fluids and solids with tracer diffusion in the solid

Cited by 64 publications

References 4 publications

Oxygen nonstoichiometry, defect structure and oxygen diffusion in the double perovskite GdBaCo2O6−δ

Oxygen nonstoichiometry, defect structure and oxygen diffusion in the double perovskite GdBaCo2O6−δ

Oxygen tracer diffusion and surface exchange kinetics in Ba0.5Sr0.5Co0.8Fe0.2O3−δ

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

Contact Info

Product

Resources

About

Oxygen nonstoichiometry, defect structure and oxygen diffusion in the double perovskite GdBaCo₂O_6−δ

Oxygen nonstoichiometry, defect structure and oxygen diffusion in the double perovskite GdBaCo₂O_6−δ