Oxygen nonstoichiometry and defect structure of undoped and doped lanthanum cobaltites / Zuev A. Yu.,Petrov A. N.,Vylkov A. I.,Tsvetkov D. S. // JOURNAL OF MATERIALS SCIENCE. - 2007. - V. 42, l. 6. - P. 1901-1908.

ISSN/EISSN:

0022-2461 / нет данных

Type:

Article; Proceedings Paper

Abstract:

The results of oxygen nonstoichiometry are presented for the perovskite-type undoped cobaltite LaCoO(3-delta), doped with strontium La(0.7)Sr(0.3)CoO(3-delta), and doped with copper LaCo(0.7)Cu(0.3)O(3-delta) as a function of oxygen partial pressure p(O2) and temperature.The modeling of the defect structure of these oxygen deficient perovskites is carried out. Two different defect structure models are evolved. Within the framework of the first model electrons are treated as quasi-free in LaCoO(3-delta), partly trapped in La(0.7)Sr(0.3)CoO(3-delta) and LaCo(0.7)Cu(0.3)O(3-delta), whereas holes are assumed to be itinerant in all oxides studied. The intrinsic electronic disordering process is taken into account as well. According to the second model electrons and holes are assumed to be localized. Thermal excited charge disproportionation of cobalt is considered as well. The corresponding equations for the law of mass action, electroneutrality condition, and mass balance give a set of nonlinear equations in the both cases. The analytical solutions of these sets yield general expressions which are used for the verification of the defect models proposed by nonlinear curve fitting. The latter showed that both models of the defect structure of all lanthanum cobaltites studied fit the experimental data about equally good. It is, therefore, difficult to rule out either of defect structure models on the basis of equilibrium data on oxygen nonstoichiometry solely.

Author keywords:

ELECTRONIC BAND-STRUCTURE; LA1-XSRXCOO3-DELTA; BEHAVIOR

DOI:

10.1007/s10853-006-0345-8

Web of Science ID:

ISI:000244889600006

Соавторы в МНС:

Другие поля

Поле	Значение
Month	MAR
Note	International Conference on Nonstoichiometric Compounds, Kauai, HI, APR 03-08, 2005
Organization	Engn Conf Int
Publisher	SPRINGER
Address	233 SPRING ST, NEW YORK, NY 10013 USA
Language	English
Keywords-Plus	ELECTRONIC BAND-STRUCTURE; LA1-XSRXCOO3-DELTA; BEHAVIOR
Research-Areas	Materials Science
Web-of-Science-Categories	Materials Science, Multidisciplinary
Author-Email	andrew.zuev@usu.ru
ResearcherID-Numbers	Tsvetkov, Dmitry/N-2491-2016 Zuev, Andrey/E-6220-2014 Vylkov, Aleksey/M-7433-2013
ORCID-Numbers	Vylkov, Aleksey/0000-0003-3988-1311
Number-of-Cited-References	16
Usage-Count-Last-180-days	2
Usage-Count-Since-2013	20
Journal-ISO	J. Mater. Sci.
Doc-Delivery-Number	145UA