@article{Lu2026, 
author = {Yutian Lu and Weijia Guo and Chongyang Zhang and Bowen Yin and Hui Zhang and Zhenxing Yue},
title = {Microwave/terahertz dielectric properties of high-Q willemite ceramics: Dual control through non-stoichiometric design and Ge4+ substitution},
year = {2026},
journal = {Journal of Materiomics},
volume = {12},
number = {2},
keywords = {Microwave dielectric property, Secondary phase, Low dielectric loss, Willemite, Terahertz spectroscopy},
url = {https://www.sciopen.com/article/10.1016/j.jmat.2025.101118},
doi = {10.1016/j.jmat.2025.101118},
abstract = {The advancement of communication technologies demands dielectric materials with superior performance characteristics, particularly low permittivity and minimal dielectric loss. This study investigates Ge4+-substituted willemite ceramics, including Zn2Si1–xGexO4 (ZS-xGe, x = 0 and 0.1) and Zn1.8Si1–yGeyO3.8 (ZS-yGe, y = 0 to 0.3), synthesized via the conventional solid-state method. The non-stoichiometric design effectively suppresses the formation of ZnO. The intrinsic and extrinsic losses of the ZS-xGe ceramics are separated by a systematic comparative analysis of the dielectric losses in the terahertz band, and the extrinsic losses are fitted by the Drude term in the Lorentz-Drude dielectric response model. Consequently, ZS-yGe ceramics exhibit lower εr and significantly improved Q×f values across microwave to terahertz band. In ZnO-free ceramics, Ge4+ substitution enhances the ionic polarizability, the unit cell volume and the bond strain, increasing εr and Q×f values (decreasing intrinsic losses), and decreasing τf. The optimized Zn1.8Si0.9Ge0.1O3.8 ceramics demonstrate superior dielectric properties with εr = 6.66, Q×f = 225,500 GHz and τf = −60.0 × 10−6 °C−1 at 12.45 GHz, and εr = 7.02, Q×f = 401,800 GHz at 1 THz. These novel ceramics are positioned as promising candidates for next-generation microwave and terahertz communication devices.}
}