Abstract Li 2 Mg 3 Ti 1-X (Mg 1/3 Nb 2/3 ) X O 6 (0 ≤x ≤ 0.25) ceramics were prepared by a conventional solid-state reaction process. Their crystal structures, sintering characteristics, Raman spectra and microwave dielectric properties were then investigated. XRD patterns of the sintered samples indicated that all compositions showed a single phase and the rock-salt structure. As the (Mg 1/3 Nb 2/3 ) 4+ contents increase, the variations of e r values showed a downward trend, which could be explained by the changes of polarizabilities and the shift of Raman vibration modes. Q·f values initially increased to a maximum value and then decreased with increasing of x values. In addition, τ f values decreased almost linearly with the x values, which significantly correlated with the thermal expansion coefficient. Excellent combined microwave dielectric properties with e r = 14.79, Q·f = 204,900 GHz and τ f = −18.43 ppm/°C were obtained for Li 2 Mg 3 Ti .95 (Mg 1/3 Nb 2/3 ) .05 O 6 ceramic sintered at 1550 °C.

中文翻译：

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Li 2 Mg 3 Ti 1-x (Mg 1/3 Nb 2/3 ) x O 6 (0≤x≤0.25)陶瓷的晶体结构、拉曼光谱和微波介电性能

摘要 采用常规固相反应工艺制备了Li 2 Mg 3 Ti 1-X (Mg 1/3 Nb 2/3 ) XO 6 (0 ≤x ≤ 0.25)陶瓷。然后研究了它们的晶体结构、烧结特性、拉曼光谱和微波介电特性。烧结样品的 XRD 谱表明所有成分都显示出单相和岩盐结构。随着(Mg 1/3 Nb 2/3 ) 4+ 含量的增加，er值的变化呈下降趋势，这可以用极化率的变化和拉曼振动模式的转变来解释。Q·f 值最初增加到最大值，然后随着 x 值的增加而减小。此外，τ f 值与 x 值几乎呈线性下降，这与热膨胀系数显着相关。