Premium
Effects of Silver on Barium Titanate as a Function of Stoichiometry
Author(s) -
Byrne Tiffany A.,
Cann David P.
Publication year - 2004
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.1551-2916.2004.00875.x
Subject(s) - stoichiometry , solubility , materials science , crystallite , barium titanate , dielectric , perovskite (structure) , barium , microstructure , sintering , analytical chemistry (journal) , mineralogy , inorganic chemistry , crystallography , chemistry , metallurgy , organic chemistry , optoelectronics
This work examines the effects of Ag on stoichiometric and nonstoichiometric BaTiO 3 in terms of the unit cell dimensions, the polycrystalline microstructure, and the dielectric properties. Stoichiometric BaTiO 3 and compositions with 0.5 mol% TiO 2 excess and 0.5 mol% BaO excess were prepared via solid‐state synthesis with varying amounts of Ag up to 0.3 mol%. Experimental results indicate that stoichiometry plays a significant role in the solubility of Ag and its effects on the physical properties. Overall, the solubility of Ag was negligible in stoichiometric BaTiO 3 . However, compositions with excess TiO 2 stabilized the solubility of Ag as evidenced from changes in the unit cell dimensions and dielectric properties. Based on these data, it is proposed that Ag occupies the A‐site in the perovskite structure with an upper limit of Ag solubility of 0.06 mol% Ag in BaTiO 3 with 0.5 mol% excess TiO 2 . Dielectric measurements showed that Ag concentrations approaching 0.3 mol% gave rise to an increase in the space charge effect, especially at temperatures above T C . In both nonstoichiometric compositions, the presence of a liquid Ag phase during thermal processing was found to affect microstructural development and sintering.