Zhou, D. orcid.org/0000-0001-7411-4658, Zhang, L., Xu, D.-M. et al. (12 more authors) (2023) Novel method to achieve temperature-stable microwave dielectric ceramics: a case in the fergusonite-structured NdNbO4 system. ACS Applied Materials & Interfaces, 15 (15). ISSN 1944-8244
Abstract
Microwave dielectric ceramics with permittivity (εr) ∼ 20 play an important role in massive multiple-input multiple-output (MIMO) technology in 5G. Although fergusonite-structured materials with low dielectric loss are good candidates for 5G application, tuning the temperature coefficient of resonant frequency (TCF) remains a problem. In the present work, smaller V5+ ions (rV = 0.355 Å, with coordination number (CN) = 4) were substituted for Nb5+ (rNb = 0.48 Å with CN = 4) in the Nd(Nb1–xVx)O4 ceramics, which, according to in situ X-ray diffraction data, lowered the fergusonite-to-scheelite phase transition (TF-S) to 400 °C for x = 0.2. The thermal expansion coefficient (αL) of the high-temperature scheelite phase was +11 ppm/°C, whereas for the low-temperature fergusonite phase, it was + 14 < αL < + 15 ppm/°C. The abrupt change in αL, the associated negative temperature coefficient of permittivity (τε), and the minimum value of εr at TF-S resulted in a near-zero TCF ∼ (+7.8 ppm/°C) for Nd(Nb0.8V0.2)O4 (εr ∼ 18.6 and Qf ∼ 70,100 GHz). A method to design near-zero TCF compositions based on modulation of τε and αL at TF-S is thus demonstrated that may also be extended to other fergusonite systems.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © © 2023 American Chemical Society. This is an author-produced version of a paper subsequently published in ACS Applied Materials & Interfaces. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | dielectric resonator; fergusonite; microwave dielectric ceramics; scheelite; temperature coefficient of resonant frequency |
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: | 19 Apr 2023 11:27 |
Last Modified: | 05 Apr 2024 00:13 |
Status: | Published |
Publisher: | American Chemical Society (ACS) |
Refereed: | Yes |
Identification Number: | 10.1021/acsami.2c23180 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:198314 |