Publication: Structural and microwave dielectric properties of temperature-stable Ca1-xEuxMo1-xNbxO4 ceramics for dielectric resonator antenna applications
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Issued Date
2025-10-15
Resource Type
ISSN
09258388
Scopus ID
2-s2.0-105017004745
Journal Title
Journal of Alloys and Compounds
Volume
1042
Rights Holder(s)
SCOPUS
Bibliographic Citation
Journal of Alloys and Compounds Vol.1042 (2025)
Suggested Citation
Gu X., Tang Y., Wu J., Zhang N., Zhang S., Hu C., Pulphol P., Vittayakorn N., Xiang H., Fang L. Structural and microwave dielectric properties of temperature-stable Ca1-xEuxMo1-xNbxO4 ceramics for dielectric resonator antenna applications. Journal of Alloys and Compounds Vol.1042 (2025). doi:10.1016/j.jallcom.2025.184066 Retrieved from: https://hdl.handle.net/20.500.14740/50570
Corresponding Author(s)
Other Contributor(s)
Abstract
Ca<inf>1-x</inf>Eu<inf>x</inf>Mo<inf>1-x</inf>Nb<inf>x</inf>O<inf>4</inf> (0.1 ≤ x ≤ 0.7) ceramics were synthesized through the co-substitution of Ca<sup>2+</sup> and Mo<sup>6+</sup> in CaMoO<inf>4</inf> using Eu<sup>3+</sup> and Nb<sup>5+</sup>. All samples exhibited tetragonal scheelite structures within the range of 0.1 ≤ x ≤ 0.6. However, at x = 0.7, a monoclinic fergusonite structure was observed, as the [Nb/MoO<inf>4</inf>] tetrahedron at the B-site transforms into a [Nb/MoO<inf>6</inf>] octahedron. As the substitution amount increases, ε<inf>r</inf> (11.39–16.40), Q×f (21,950–82,930 GHz), and τ<inf>f</inf> (−47.72 to +8.01 ppm/℃) all show a gradual increase. Notably, the τ<inf>f</inf> value of this system can shift from negative to positive. The structural influence mechanism on the microwave dielectric properties in Ca<inf>1-x</inf>Eu<inf>x</inf>Mo<inf>1-x</inf>Nb<inf>x</inf>O<inf>4</inf> ceramics was clarified through various analytical methods, including ion polarizability, P-V-L chemical bond theory, bond valence theory, density of states (DOS), and electron localization function (ELF). Additionally, a resonant antenna designed and simulated using Ca<inf>0.4</inf>Eu<inf>0.6</inf>Mo<inf>0.4</inf>Nb<inf>0.6</inf>O<inf>4</inf> meets the requirements for satellite communication.