Interaction of Silver/palladium Electrodes with Lead-and Bismuth-based Electroceramics

Abstract

In this study the phase relations between Pd or 70Ag/30Pd electrode systems with commercially important Bi-or Pb-based oxides were determined to establish the conditions under which detrimental interfacial chemical reactions may occur. For the reaction of Pd with Bi compounds, PdBi2O4 formation was observed if the reaction proceeded at temperatures less than 835°C. at higher temperatures a Pd (Bi) alloy formed containing the maximum solubility of the Bi, i.e., 16 at.%. For the reaction of Pd with Pb compounds, a Pd (Pb) alloy formed which in all instances exhibited the maximum solubility of the Pb, i.e., 14 at.%. These reactions had an adverse effect on the local stoichiometry and composition of the dielectric, causing depletion of Bi or Pb. Studies on commercial capacitor dielectrics from DuPont (X7R and Z5U formulations) and Pb (Mg1/3Nb2/3)O3 showed that the use of Pd electrodes decreased the dielectric constant substantially, which was due to the formation of a low permittivity phase in series connectivity with the unaltered dielectric.

Department(s)

Materials Science and Engineering

International Standard Serial Number (ISSN)

0002-7820; 1551-2916

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 1993 Wiley-Blackwell, All rights reserved.

Publication Date

01 Feb 1993

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