Publication: Crystal structure, microwave dielectric properties and antenna simulation of low-permittivity Eu2CaMGa4O12(M = Ti, Sn, Zr) garnets
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Issued Date
2025-12-01
Resource Type
ISSN
02728842
Scopus ID
2-s2.0-105025568664
Journal Title
Ceramics International
Volume
51
Issue
30
Start Page
65464
End Page
65472
Rights Holder(s)
SCOPUS
Bibliographic Citation
Ceramics International Vol.51 No.30 (2025) , 65464-65472
Suggested Citation
Yang Y., Wang Z., Qiu H., Fang W., Tang Y., Li J., Xiang H., Pulphol P., Vittayakorn N., Fang L. Crystal structure, microwave dielectric properties and antenna simulation of low-permittivity Eu2CaMGa4O12(M = Ti, Sn, Zr) garnets. Ceramics International Vol.51 No.30 (2025) , 65464-65472. 65472. doi:10.1016/j.ceramint.2025.11.224 Retrieved from: https://hdl.handle.net/20.500.14740/55004
Corresponding Author(s)
Other Contributor(s)
Abstract
The rattling of cations plays a vital role in energy loss mechanisms and is a fundamental approach for tuning dielectric performance. In this work, phase-pure garnets with the general formula Eu<inf>2</inf>CaMGa<inf>4</inf>O<inf>12</inf> (M = Ti, Sn, Zr) were successfully synthesized. The Eu<inf>2</inf>CaZrGa<inf>4</inf>O<inf>12</inf>, Eu<inf>2</inf>CaSnGa<inf>4</inf>O<inf>12</inf>, and Eu<inf>2</inf>CaTiGa<inf>4</inf>O<inf>12</inf> ceramics were obtained through sintering at 1400°C–1500°C for 6 h. The ceramics sintered at 1450°C exhibited favorable microwave dielectric performance with low ε<inf>r</inf> values of 10.74 (for Sn), 12.34 (for Zr) and 13.66 (for Ti), high Q×f values of 83,500 GHz (for Sn), 72,800 GHz (for Zr) and 59,200 GHz (for Ti), as well as negative τ<inf>f</inf> values of −60.60 ppm/°C (for Sn), −57.20 ppm/°C (for Zr) and −48.20 ppm/°C (for Ti). In Eu<inf>2</inf>CaMGa<inf>4</inf>O<inf>12</inf> (M = Ti, Sn, Zr) ceramics, the “rattling” effect of Eu<sup>3+</sup>and Ga<sup>3+</sup>dominated a slight overall structural expansion, which, in turn, led to the higher ε<inf>r</inf> compared to the theoretical prediction (ε<inf>r(C-M)</inf>) and contributed to the negative τ<inf>f</inf>. The variation in the Q × f values of the ceramics exhibited a negative correlation with the FWHM of the A<inf>1g</inf> Raman mode. Furthermore, due to the ultra-low loss of Eu<inf>2</inf>CaSnGa<inf>4</inf>O<inf>12</inf> ceramic, a dielectric resonator antenna was designed. This demonstrates the promising potential of the ceramics for 5G communication applications.