Crystal structure, lattice vibration and microwave dielectric properties of 3CaO·2SiO2·xCaF2 (0 ≤ x ≤ 1.5) ceramics
Crystal structure, lattice vibration and microwave dielectric properties of 3CaO·2SiO2·xCaF2 (0 ≤ x ≤ 1.5) ceramics
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3CaO·2SiO2·xCaF2(0≤x≤1.5)陶瓷的晶体结构、晶格振动及微波介电性能
DOI：
10.1016/j.ceramint.2022.01.328
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发表时间：
2022
影响因子：
5.2
通讯作者：
Yongxiang Li
中科院分区：
文献类型：
--
作者：
Jincheng Qin;Zhifu Liu;Mingsheng Ma;Yongxiang Li
研究了3CaO·2SiO2·xCaF2陶瓷的晶体结构、晶格振动和微波介电性能。随着x值的增加，3CaO·2SiO2·xCaF2陶瓷的晶体结构由蓝晶石(Ca3Si2O7)转变为尖晶石(Ca4Si2O7F2)。振动能的增加和[SiO4]四面体单元的收缩阻碍了离子极化，从而降低了相对介电常数(εr)。Si-O伸缩峰半高宽的增大反映了更加剧烈的非简谐晶格振动，导致了较低的品质因数(Q×f值)。O/F-Ca-O/F弯曲峰的拉曼频移与谐振频率温度系数(τf)呈正相关。εr和Q×f值(∼@11 GHz)的微波介电性能分别在7.89~8.42GHz和21805~46098 GHz之间变化。在20~110 GHz频率范围内具有稳定的复介电常数(εr∗)，这表明氟化橙石陶瓷有望成为微波器件应用的候选材料。
The crystal structure, lattice vibration and microwave dielectric properties of 3CaO· 2SiO 2· xCaF 2 ceramics were investigated in this work. With the increasing of x value, the crystal structure of 3CaO· 2SiO 2· xCaF 2 ceramics transfers from rankinite (Ca 3 Si 2 O 7) to cuspidine (Ca 4 Si 2 O 7 F 2). The increase of the vibration energy and shrinkage of [SiO 4] tetrahedral unit hampers the ionic polarization and thus reduces relative permittivity (ε r). The enlarged FWHM of the Si–O stretching peak reflects a more drastic anharmonic lattice vibration, resulting in a lower quality factor (Q× f value). The Raman shift of O/F–Ca–O/F bending peak is positively correlated with the temperature coefficient of resonant frequency (τ f). The microwave dielectric properties of ε r and Q× f value (∼@ 11 GHz) ranging from 7.89 to 8.42, and 21805–46098 GHz, respectively. The stable complex permittivity (ε r∗) in the frequency range of 20–110 GHz indicates that the fluoride cuspidine ceramics could be a promising candidate for microwave device applications.