Thallium substitution in the bismuth-oxygen layer of Aurivillius phases

Authors
Millan, P Castro, A
Citation
P. Millan et A. Castro, Thallium substitution in the bismuth-oxygen layer of Aurivillius phases, MATER RES B, 34(1), 1999, pp. 25-34
Citations number
26
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
MATERIALS RESEARCH BULLETIN
ISSN journal
00255408 → ACNP
Volume
34
Issue
1
Year of publication
1999
Pages
25 - 34
Database
ISI
SICI code
0025-5408(19990101)34:1<25:TSITBL>2.0.ZU;2-A
Abstract
New substituted Aurivillius phases of general compositions Bi2-xTlxSrNb2O9- x, Bi2-yTlySr1-2yLa2yNb2O9, and Bi2-zTlzSr1-zLazNb2 O9-z/2 have been synthe sized. The extent of the substitution in each solid solution has been corre lated with the size of the cations and the simultaneous creation of oxygen vacancies in the network. Steric considerations suggest the preferential lo cation of oxygen vacancies in the bismuth, thallium-oxygen layer. Impedance spectroscopy measurements have shown a similar electrical behavior of oxyg en-deficient and nondeficient phases; this fact has been explained as due t o the high energy barriers to oxygen ion migration in the bismuth layer of Aurivillius phases. (C) 1999 Elsevier Science Ltd.