Abstract A series of Li4Mg3[Ti1-x(Mg1/3Ta2/3)x]2O9 (LMT1-x(MT)x) (x = 0–0.4) ceramics were prepared via the traditional solid-state method. The effects of the substitution of (Mg1/3Ta2/3)4+ on the sintering characteristic, crystal structure, phase composition and dielectric properties of Li4Mg3Ti2O9 ceramics were investigated for the first time. The analysis of the X-ray diffraction pattern indicated that the pure cubic Li4Mg3Ti2O9 phase could be formed in the whole composition range of 0 ≤x ≤ 0.4. Dense and homogeneous microstructures of LMT1-x(MT)x ceramics sintered at 1400–1550 °C could be revealed from the scanning electric microscope. The optimum microwave dielectric properties, with a permittivity 15.77, a quality factor 160,575 GHz (at 8.38 GHz) and a τf value 0 ppm/°C, were achieved in the Li4Mg3[Ti0.8(Mg1/3Ta2/3)0.2]2O9 ceramic sintered at 1550 °C.

中文翻译：

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Li4Mg3[Ti1-x(Mg1/3Ta2/3)x]2O9 (x=0-0.4)陶瓷的晶体结构和微波介电性能

摘要 采用传统固相法制备了一系列 Li4Mg3[Ti1-x(Mg1/3Ta2/3)x]2O9 (LMT1-x(MT)x) (x = 0-0.4) 陶瓷。首次研究了(Mg1/3Ta2/3)4+取代对Li4Mg3Ti2O9陶瓷的烧结特性、晶体结构、相组成和介电性能的影响。X射线衍射图分析表明，在0≤x≤0.4的整个组成范围内可以形成纯立方Li4Mg3Ti2O9相。在 1400–1550 °C 下烧结的 LMT1-x(MT)x 陶瓷的致密且均匀的微观结构可以从扫描电镜中看到。在 Li4Mg3[Ti0.8(Mg1/3Ta2/3)0 中实现了最佳微波介电特性，介电常数为 15.77，品质因数为 160,575 GHz（在 8.38 GHz），τf 值为 0 ppm/°C。