Paper Title:
Defect Formation in La2Ni(M)O4+δ (M= Co, Cu): Modelling and Coulometric Titration Study
  Abstract

The p(O2)-T- diagrams of La2Ni1-xMxO4+ (M=Co and Cu, x= 0-0.20), determined by the coulometric titration technique at 923-1223 K in the oxygen partial pressure range 10-4 to 0.6 atm, can be adequately described by equilibrium processes of oxygen intercalation into the rock-salt type layers and hole localization on B-site cations forming 3+ oxidation states. For the hole activity, a non-ideal solution model taking into account the repulsion of p-type electronic charge carriers can be used. The electrostatic repulsion excludes occupation of nearest neighboring sites and leads to splitting of the energy levels for more distant sites. The affinity of Ni and Cu cations with respect to the hole localization is similar and cannot be statistically separated analyzing the oxygen nonstoichiometry data only. On the contrary, cobalt cations tend to remain in the trivalent state and Co3+ should be treated as a separate type of charged point defect. Oxygen vacancies formed in the perovskite-like layers due to intrinsic Frenkel disorder have no essential effect on the oxygen thermodynamics. As expected, the thermodynamic functions governing the intercalation-related processes are independent of defect concentrations.

  Info
Periodical
Materials Science Forum (Volumes 514-516)
Edited by
Paula Maria Vilarinho
Pages
397-401
DOI
10.4028/www.scientific.net/MSF.514-516.397
Citation
E.N. Naumovich, M. V. Patrakeev, V. V. Kharton, A. A. Yaremchenko, E. V. Tsipis, D. I. Logvinovich, J. R. Frade, F. M.B. Marques, "Defect Formation in La2Ni(M)O4+δ (M= Co, Cu): Modelling and Coulometric Titration Study", Materials Science Forum, Vols. 514-516, pp. 397-401, 2006
Online since
May 2006
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Andréy V. Kovalevsky, D.V. Sviridov, Vladislav V. Kharton, E.N. Naumovich, Jorge R. Frade
Abstract:Ceramic anodes, made of perovskite-type rare-earth and strontium cobaltites substituted in both sublattices, exhibit a high electrocatalytic...
377
Authors: Ivan P. Marozau, Vladislav V. Kharton, Jorge R. Frade, Fernando M.B. Marques
Abstract:Oxygen transport properties of perovskite-type SrCe1-xYxO3-δ (x = 0.05–0.10), exhibiting protonic transport in hydrogen-containing reducing...
387
Authors: Vladislav V. Kharton, A.P. Viskup, Andréy V. Kovalevsky, A.L. Shaula, Jorge R. Frade, Fernando M.B. Marques
Abstract:Due to relatively high oxygen permeability, lanthanum-strontium ferrite phases are of interest as ceramic membrane materials for the partial...
402
Authors: D. Schlehuber, Egbert Wessel, Lorenz Singheiser, T. Markus
Abstract:One possibility to run a zero CO2-emission power plant is the oxyfuel combustion process. An efficient technology to separate oxygen from air...
551
Authors: Jong Pyo Kim, Dae Woong Pyo, Edoardo Magnone, Jung Hoon Park
Chapter 10: Metal
Abstract:ReBaCo2O5+δ (Re=Pr, Nd, Y) oxides were synthesized by solid state reaction method. The oxygen permeation flux of...
959