Abstract The Li 2 MgTi 1-x (Mg 1/3 Nb 2/3 ) x O 4 (0 ≤x ≤ 0.5) ceramics were prepared by the conventional solid-state method. The relationship among phase composition, substitution amount and microwave dielectric properties of the ceramics was symmetrically investigated. All the samples possess the rock salt structure with the space group of Fm- 3 m . As the x value increases from 0 to 0.5, the dielectric constant linearly decreases from 16.75 to 15.56, which can be explained by the variation of Raman spectra and infrared spectra. The Q·f value shows an upward tendency in the range of 0 ≤x ≤ 0.3, but it then decreases when x > 0.3. In addition, the temperature coefficient of resonant frequency ( τ f ) is shifted toward zero with the increasing (Mg 1/3 Nb 2/3 ) 4+ addition. By comparison, the Li 2 MgTi 0.7 (Mg 1/3 Nb 2/3 ) 0.3 O 4 ceramics sintered at 1400 °C can achieve an excellent combination of microwave dielectric properties: e r = 16.19, Q·f = 160,000 GHz and τ f = −3.14 ppm/°C.

中文翻译：

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Li 2 MgTi 1-x (Mg 1/3 Nb 2/3 ) x O 4 陶瓷在微波频率下的相组成、拉曼光谱、红外光谱和介电性能

摘要 采用常规固相法制备了Li 2 MgTi 1-x (Mg 1/3 Nb 2/3 ) x O 4 (0 ≤x ≤ 0.5)陶瓷。对称地研究了陶瓷的相组成、取代量和微波介电性能之间的关系。所有样品均具有岩盐结构，空间群为Fm-3 m。随着 x 值从 0 增加到 0.5，介电常数从 16.75 线性下降到 15.56，这可以用拉曼光谱和红外光谱的变化来解释。Q·f 值在 0 ≤x ≤ 0.3 范围内呈上升趋势，但在 x > 0.3 时下降。此外，随着(Mg 1/3 Nb 2/3 ) 4+ 添加量的增加，谐振频率的温度系数(τ f )向零偏移。相比之下，Li 2 MgTi 0.7 (Mg 1/3 Nb 2/3 ) 0.