Premium
Stoichiometric Dependence of the Aging Phenomena in Lead Iron Tungstate Ceramics
Author(s) -
Zhou Liqin,
Vilarinho Paula M.,
Baptista João L.
Publication year - 1996
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1996.tb08994.x
Subject(s) - tungsten , stoichiometry , materials science , tungstate , isothermal process , oxygen , crystallographic defect , scheelite , ceramic , crystallography , chemistry , metallurgy , thermodynamics , physics , organic chemistry
Lead iron tungstate, Pb(Fe 2/3 W 1/3 )O 3 , ceramics with different stoichiometries were used to study the isothermal aging of this relaxor ferroelectric. The tungsten‐deficient samples showed evident aging effects, more pronounced as the tungsten deficiency increased. The aging behavior showed a strong dependence on the frequency, a log‐linear function of the aging time, and a shift of the dielectric distortion with the aging temperature. Defect associations between tungsten and oxygen vacancies seemed to be responsible for this behavior. On the other hand, lead‐deficient samples showed no aging phenomena. The structural positions of point defects, tungsten, lead, and oxygen vacancies and the reorientation of defect dipole pairs have been discussed for the compositions and suggested to be responsible for the observed behavior.