Loading...
Crystal structure, microwave dielectric properties and antenna simulation of low-permittivity Eu2CaMGa4O12(M = Ti, Sn, Zr) garnets
Author(s)
Yang, Yang
Wang, Zhaohui
Qiu, Huizi
Fang, Weishuang
Tang, Ying
Li, Jie
Xiang, Huaicheng
Pulphol, Phieraya
Fang, Liang
Date Issued
December 1, 2025
Type
Article
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 Eu2CaMGa4O12 (M = Ti, Sn, Zr) were successfully synthesized. The Eu2CaZrGa4O12, Eu2CaSnGa4O12, and Eu2CaTiGa4O12 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 εr 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 τf values of −60.60 ppm/°C (for Sn), −57.20 ppm/°C (for Zr) and −48.20 ppm/°C (for Ti). In Eu2CaMGa4O12 (M = Ti, Sn, Zr) ceramics, the “rattling” effect of Eu3+and Ga3+dominated a slight overall structural expansion, which, in turn, led to the higher εr compared to the theoretical prediction (εr(C-M)) and contributed to the negative τf. The variation in the Q × f values of the ceramics exhibited a negative correlation with the FWHM of the A1g Raman mode. Furthermore, due to the ultra-low loss of Eu2CaSnGa4O12 ceramic, a dielectric resonator antenna was designed. This demonstrates the promising potential of the ceramics for 5G communication applications.
Citation
Ceramics International, 51(30), 65464-65472, 2025