Zhou, D. orcid.org/0000-0001-7411-4658, Pang, L.-X., Wang, D.-W. orcid.org/0000-0001-6957-2494 et al. (1 more author) (2019) Novel water-assisting low firing MoO3 microwave dielectric ceramics. Journal of the European Ceramic Society, 39 (7). pp. 2374-2378. ISSN 0955-2219
Abstract
MoO3 ceramics can not be well densified via conventional solid state method and a low relative density (ρ) was obtained (˜64.5% at 680 °C) with a permittivity (εr) ˜ 7.58, a quality factor (Qf) ˜ 35,000 GHz and a temperature coefficient of resonant frequency (TCF) ˜ − 39 ppm/°C. However, cold sintering at 150 °C using 4 wt. % H2O at 150 MPa enhanced densification and give a relative ρ ˜76.8% and εr ˜ 8.31 but with a Qf of only ˜ 900 GHz. The addition of (NH4)6Mo7O24·4H2O further improved densification to give a relative ρ ˜ 83.7% after annealing at 700 °C, resulting in a εr ˜ 9.91 with a Qf ˜ 11,800 GHz. We conclude therefore that oxides that are difficult to be sintered via a conventional solid state route may benefit from cold sintering but despite the higher density, lower Qf cannot be avoided due to the impurities and grain boundary phases that are introduced.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2019 Elsevier. This is an author produced version of a paper subsequently published in Journal of the European Ceramic Society. Uploaded in accordance with the publisher's self-archiving policy. Article available under the terms of the CC-BY-NC-ND licence (https://creativecommons.org/licenses/by-nc-nd/4.0/). |
Keywords: | Ceramics; Microwave dielectrics |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Materials Science and Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 18 Feb 2019 11:37 |
Last Modified: | 18 Nov 2021 09:56 |
Status: | Published |
Publisher: | Elsevier |
Refereed: | Yes |
Identification Number: | 10.1016/j.jeurceramsoc.2019.01.052 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:142620 |