Brown, T, Brown, AP orcid.org/0000-0001-9692-2154, Hall, DA et al. (5 more authors) (2021) New high temperature dielectrics: Bi-free tungsten bronze ceramics with stable permittivity over a very wide temperature range. Journal of the European Ceramic Society, 41 (6). pp. 3416-3424. ISSN 0955-2219
Abstract
High relative permittivity, εr, over a very wide temperature range, −65 ⁰C to 325 ⁰C, is presented for ceramics designed to be compatible with base metal electrode multilayer capacitor manufacturing processes. We report a ≥ 300 ⁰C potential Class II capacitor material, free from Bi or Pb ions, developed by doping Sr2NaNb5O15 with Ca2+, Y3+ and Zr4+ ions, according to the formulation Sr2−2zCazYzNaNb5-zZrzO15. For sample composition z = 0.025, εr values are 1565 ± 15 % (1 kHz) from −65 °C to 325 °C. At a slightly higher level of doping, z = 0.05, εr values are 1310 ± 10 % from −65 °C to 300 °C. Values of the dielectric loss tangent, tanδ are ≤ 0.025 from −60 °C to 290 °C, for z = 0.025, with tanδ increasing to 0.035 at 325 ⁰C. Microstructural analyses exclude core-shell mechanisms being responsible for the flattening of the εr –T response.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2020 Published by Elsevier Ltd. This is an author produced version of a paper published in Journal of the European Ceramic Society. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | High temperature dielectrics; Bi-free; Pb-free; Tungsten bronze; Microstructure |
Dates: |
|
Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 16 Dec 2020 12:28 |
Last Modified: | 21 Oct 2021 00:38 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.jeurceramsoc.2020.10.034 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:169036 |