Defect equilibria and partial molar properties of (La,Sr)(Co,Fe)O3-delta / Bucher E.,Sitte W.,Caraman G. B.,Cherepanov V. A.,Aksenova T. V.,Ananyev M. V. // SOLID STATE IONICS. - 2006. - V. 177, l. 35-36, SI. - P. 3109-3115.

ISSN/EISSN:

0167-2738 / нет данных

Type:

Article; Proceedings Paper

Abstract:

The oxygen nonstoichiometry delta of La1-xSrxCo1-yFeyO3-delta (x=0.6 and y=0.2, 0.4) was investigated by thermogravimetry in the range 703 <= T/degrees C <= 903 and 1E-5 < pO(2)/atm < 1. The oxygen deficit increases with increasing T and decreasing pO(2). Electronic conductivities sigma were measured as a function of pO(2) in the range 1E-5 < pO(2)/atm < 1 at 700 <= 5 T/degrees C <= 900. At constant T, a p-type pO(2)-dependence of sigma is observed. Oxygen nonstoichiometry data are analyzed with regard to the enthalpy and entropy of oxidation Delta H-ox(theta) and Delta S-ox(theta), as well as to the partial molar enthalpy and entropy of oxygen with respect to the standard state of oxygen (pO(2)(theta) = 1 atm), (h(O) - H-O(theta)) and (s(O) - S-O(theta), respectively. For 2.67 <= (3-delta) <= 2.79, (h(O) - H-O(theta)) decreases with increasing delta, while (s(O) - S-O(theta)) is constant within the limits of error. Defect chemical modelling was performed by an ideal solution model under consideration of three different valence states for B-site ions (Co or Fe). The dependence of a on delta is modelled, using calculated defect concentrations as functions of delta. Deviations from the ideal behaviour suggest an immobilization of n-type charge carriers by oxygen vacancies. (c) 2006 Elsevier B.V. All rights reserved.

Author keywords:

perovskite; LSCF; oxygen nonstoichiometry; electronic conductivity; enthalpy of oxidation; partial molar properties TEMPERATURE ELECTRICAL-CONDUCTIVITY; PEROVSKITE-TYPE OXIDES; SEEBECK COEFFICIENT; REDOX ENERGETICS; THERMODYNAMIC QUANTITIES; OXYGEN NONSTOICHIOMETRY; ELECTRONIC CONDUCTIVITY; COULOMETRIC TITRATION; PHASE-EQUILIBRIA; SOLID-SOLUTIONS

DOI:

10.1016/j.ssi.2006.07.062

Web of Science ID:

ISI:000242888300019

Соавторы в МНС:

Другие поля

Поле	Значение
Month	NOV 30
Note	Symposium on Solid State Ionics, Nice, FRANCE, MAY 29-JUN 02, 2006
Organization	European Mat Res Soc
Publisher	ELSEVIER SCIENCE BV
Address	PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
Language	English
Keywords-Plus	TEMPERATURE ELECTRICAL-CONDUCTIVITY; PEROVSKITE-TYPE OXIDES; SEEBECK COEFFICIENT; REDOX ENERGETICS; THERMODYNAMIC QUANTITIES; OXYGEN NONSTOICHIOMETRY; ELECTRONIC CONDUCTIVITY; COULOMETRIC TITRATION; PHASE-EQUILIBRIA; SOLID-SOLUTIONS
Research-Areas	Chemistry; Physics
Web-of-Science-Categories	Chemistry, Physical; Physics, Condensed Matter
Author-Email	bucher@unileoben.ac.at
ResearcherID-Numbers	Cherepanov, Vladimir/E-6451-2014 Ananyev, Maxim/F-5104-2014
ORCID-Numbers	Cherepanov, Vladimir/0000-0003-3653-6459 Ananyev, Maxim/0000-0002-2254-0193 Bucher, Edith/0000-0002-9017-9555
Number-of-Cited-References	43
Usage-Count-Last-180-days	3
Usage-Count-Since-2013	27
Journal-ISO	Solid State Ion.
Doc-Delivery-Number	117QP