Ca/Zr协同置换对CaSmAlO4基陶瓷显微结构与微波介电性能的影响

通过传统固相合成法成功制备了层状钙钛矿结构Ca_1+xSm_1?xAl_1?xZr_xO₄（x=0.1，0.2，0.3，0.4）微波陶瓷。利用X射线衍射、拉曼光谱、电子背散射衍射、能谱及矢量网络分析表征了Ca/Zr协同置换对微波陶瓷材料晶体结构、微观形貌及介电性能的影响。结果表明，随着x值的增加，晶胞参数（a、c）和晶胞体积（V_cell）增大，理论极化率（α_theo）增加，进而导致了介电常数（ε_r）和谐振频率温度系数（τ_f）增大；协同置换引入的适量CaO第二相有利于品质因子（Q×f）的提高。当x=0.2时，Ca_1.2Sm_0.8Al_0.8Zr_0.2O₄陶瓷呈现出良好的微波性能，介电常数为20.16，品质因子为72489，谐振频率温度系数为?3.46×10?6·℃?1。

Effect of Ca/Zr co-substitution on microstructure and microwave dielectric characteristics of CaSmAlO4-based ceramics

Ca_1+xSm_1?xAl_1?xZr_xO₄ (x=0.1, 0.2, 0.3, 0.4) microwave ceramics in the lamellar perovskite structure were fabricated by the traditional solid-phase synthesis method. The effect of the Ca/Zr co-substitution on the crystal structure, microstructure, and dielectric characteristics of the microwave ceramics were investigated by X-ray diffraction (XRD), Raman spectra, electron backscatter diffraction (EBSD), energy dispersive spectroscopy (EDS), and vector network analysis (VNA). In the results, the cell parameters (a, c), cell volume (V_cell), and theoretical polarizability (α_theo) increase with the increase of x, leading to the increase of the dielectric constant (ε_r) and resonant frequency temperature coefficient (τ_f); meanwhile, a moderate amount of CaO secondary phases can improve the quality factor (Q×f). Ca_1.2Sm_0.8Al_0.8Zr_0.2O₄ (x=0.2) ceramics show the excellent microwave performance as ε_r=20.16, Q×f=72489, and τ_f = ?3.46×10?6·℃?1.