Abstract (1- x )CaTiO 3 - x (Li 0.5 Sm 0.5 )TiO 3 (0.7 ≤ x ≤ 0.8, CLST) ceramics with an orthorhombic perovskite structure were fabricated by a conventional solid-state reaction method. The effects of composition variation on the microwave dielectric properties were studied in detail. The permittivity (e r ) and quality factor (Q × f ) value decreased with an increase in the x value, and the temperature coefficient of the resonant frequency (τ f ) reached nearly zero. Raman and infrared reflection spectroscopy were employed to reveal the relationship between vibrational modes and microwave dielectric properties. The Raman spectra fitted with the Lorentzian model indicated that the dielectric loss deteriorates with an increase in the x value are the result of the lowered A-site cation ordering degree. The harmonic oscillator model was used to fit the infrared reflection spectra, and the obtained complex dielectric response was extrapolated down to the microwave region. The infrared reflection spectra show that the vibrational modes related to A-site cations at lower frequencies (i.e., −1 ) play the most important role in the microwave dielectric properties of CLST ceramics. The optimal microwave dielectric properties were found to be e r = 109.4, Q × f = 4698 GHz, and τ f = 1.6 ppm/°C in the sample of 0.22CaTiO 3 -0.78(Li 0.5 Sm 0.5 )TiO 3 .

中文翻译：

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(1- x ) CaTiO 3 - x (Li 0.5 Sm 0.5 )TiO 3 陶瓷中A位离子振动模式与微波介电特性的相关性

摘要 采用常规固相反应法制备了具有斜方晶钙钛矿结构的 (1- x )CaTiO 3 - x (Li 0.5 Sm 0.5 )TiO 3 (0.7 ≤ x ≤ 0.8, CLST)陶瓷。详细研究了成分变化对微波介电性能的影响。介电常数 (er ) 和品质因数 (Q × f ) 值随着 x 值的增加而减小，谐振频率的温度系数 (τ f ) 接近于零。拉曼和红外反射光谱被用来揭示振动模式和微波介电特性之间的关系。符合洛伦兹模型的拉曼光谱表明，介电损耗随着 x 值的增加而恶化，这是 A 位阳离子有序度降低的结果。谐振子模型用于拟合红外反射光谱，并将获得的复介电响应外推到微波区域。红外反射光谱表明，在较低频率（即 -1 ）下与 A 位阳离子相关的振动模式在 CLST 陶瓷的微波介电性能中起最重要的作用。发现在 0.22CaTiO 3 -0.78(Li 0.5 Sm 0.5 )TiO 3 样品中，最佳微波介电特性为 er = 109.4，Q × f = 4698 GHz，τ f = 1.6 ppm/°C。-1 ) 在 CLST 陶瓷的微波介电性能中起最重要的作用。发现在 0.22CaTiO 3 -0.78(Li 0.5 Sm 0.5 )TiO 3 样品中，最佳微波介电特性为 er = 109.4，Q × f = 4698 GHz，τ f = 1.6 ppm/°C。-1 ) 在 CLST 陶瓷的微波介电性能中起最重要的作用。发现在 0.22CaTiO 3 -0.78(Li 0.5 Sm 0.5 )TiO 3 样品中，最佳微波介电特性为 er = 109.4，Q × f = 4698 GHz，τ f = 1.6 ppm/°C。