电介质
离子半径
结构精修
拉曼光谱
材料科学
晶体结构
价(化学)
微观结构
密度泛函理论
陶瓷
微波食品加热
凝聚态物理
化学
分析化学(期刊)
矿物学
离子
计算化学
结晶学
光学
复合材料
物理
光电子学
有机化学
色谱法
量子力学
作者
Jian Li,Litao Jia,Yong Zhang,Wei Sun,Yang Wang,Haitao Wu,Ling Feng Li,Chuanbing Cheng,Yingying Wang,Ke Tan,Futian Liu
摘要
Abstract The microstructure design is important for regulating the microwave dielectric properties of materials. However, in‐depth studies on the frequency temperature stability and related micromechanism remain poorly understood. The work investigates the correlation among the sintering behavior, crystal structure, bonding nature, and microwave dielectric properties of LnPO 4 (Ln = Eu, Pr) ceramics by combining first‐principles calculations and experimental perspective. The high density ( ρ > 97%) and large grains associated with lattice expansion benefit the optimum dielectric properties: ε r = 11.24, Q × f = 61,138 GHz @ 13.311 GHz, and τ f = −30.3 ppm/°C for EuPO 4 sintered at 1500°C ( ε r = 11.35, Q × f = 63,496 GHz @ 13.042 GHz and τ f = −39.5 ppm/°C for PrPO 4 sintered at 1525°C). Bond valence analysis shows a rattling effect in [EuO 9 ] due to a smaller ionic radius. The effect induces an abnormally large polarization, effectively shifting the negative τ f toward near‐zero values. The electron localization functions, charge transfer, and bonding nature are discussed by density functional theory calculations, which illustrate stronger charge transfer and ionicity between Eu and O. This observation effectively predicts and validates the nonharmonic lattice vibrations and abnormally large polarization obtained from Raman spectrums and Rietveld refinement. These findings systematically clarify the optimized effect and micromechanism of lanthanides on the dielectric properties of monazite ceramics.
科研通智能强力驱动
Strongly Powered by AbleSci AI