Four MgO‐Ta₂O₅ ceramics with the MgO/Ta₂O₅ mole ratio x = 1, 2, 3, and 4 were prepared by traditional solid‐state reaction method, and the influence of x on the phase composition, microstructure, and dielectric properties (the dielectric constant ε_r, the temperature coefficient of resonant frequency τ_f and the quality factor Qf) of the materials was investigated using XRD, SEM, etc. The results indicated that the ceramics were composed of two crystalline phases MgTa₂O₆ and Mg₄Ta₂O₉ in the composition range studied, and that the dielectric properties ln ε, 1/Qf, and τ_f changed proportionally to the fraction of main crystal phases, which meet perfectly with the mixing model proposed in this study. It is obvious that the proportion of the two crystal phases could be precisely controlled by x, and thereby, the dielectric properties can be conveniently and precisely tailored. Our research provided a new microwave dielectric ceramic with the composition of 2MgO‐Ta₂O₅, which has an ultrahigh Qf value (211 000 GHz), low dielectric constant ε_r (19.9), and near zero temperature coefficient of resonant frequency τ_f (8 ppm/°C).

中文翻译：

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Qf值超高的MgO-Ta2O5陶瓷的相组成和微波介电性能的研究

通过传统的固态反应方法制备了四种MgO / Ta ₂ O ₅摩尔比x = 1、2、3和4的MgO-Ta ₂ O ₅陶瓷，并且x对相组成，微观结构，并用XRD，SEM等对材料的介电常数（介电常数_εr，谐振频率_τf的温度系数和品质因数Qf）进行了研究。结果表明，陶瓷是由两个晶相MgTa ₂组成的。O ₆和Mg ₄ Ta ₂ O ₉在所研究的组成范围内，介电特性lnε，1 / Qf和_τf与主晶相的分数成比例地变化，这与本研究中提出的混合模型完全吻合。显然，可以通过x精确地控制两个晶相的比例，从而可以方便且精确地调整介电性能。我们的研究提供了一种新型的微波介电陶瓷，其成分为2MgO-Ta ₂ O ₅，具有超高的Qf值（211 000 GHz），低介电常数_εr（19.9）和接近零的谐振频率温度系数_τf（8 ppm /°C）。