CaTiO₃–LnAlO₃ (Ln = La, Nd, Sm) is a perovskite-type microwave material system characterized by a moderate dielectric constant ε_r, a high quality factor Q × f, and a small temperature coefficient of resonant frequency τ_f, making this system promising for microwave devices. However, its high synthesis temperature and sintering temperature limit its industrial applications. In our work, single phase 0.7CaTiO₃–0.3Sm_0.9Nd_0.1AlO₃ (7CT–3SNA) was synthesized via the sol–gel auto combustion method using citric acid as fuel at a relatively low temperature. After being calcined at 600 °C for 2 h, well-crystallized 7CT–3SNA powders with 30–50 nm average particle size were achieved, suggesting good sintering activity. The new and narrow order band at about 800 cm⁻¹ in the Raman spectra indicates a high ordering degree in the B site of 7CT–3SNA solid solution. Compared with the solid–state reaction method and co-precipitation method, the 0.7CT–0.3SNA ceramics fabricated by the current method possess a much lower calcination temperature, a similar ε_r value, and an improved Q × f value. The optimum microwave dielectric properties of ε_r = 43.54, Q × f = 54375 GHz, and τ_f = −6.3 × 10⁻⁶/°C are obtained for the CTSA ceramics derived from the sol–gel auto combustion process. Therefore, the 7CT–3SNA ceramics prepared in this study are potential dielectric materials for microwave applications, indicating that the sol–gel auto combustion method is a good alternative strategy for the fabrication of CaTiO₃–LnAlO₃ ceramics.

的CaTiO ₃ -LnAlO ₃（Ln为镧，钕，钐）是一种钙钛矿型微波材料系统的特征在于中等介电常数ε _{- [R} ，高品质因子Q  ×  ˚F，和谐振频率的温度系数小τ _˚F，使该系统有望用于微波设备。但其较高的合成温度和烧结温度限制了其工业应用。在我们的工作中，单相 0.7CaTiO ₃ –0.3Sm _0.9 Nd _0.1 AlO ₃(7CT-3SNA) 是通过溶胶-凝胶自燃法在相对较低的温度下使用柠檬酸作为燃料合成的。在 600°C 下煅烧 2 小时后，获得了结晶良好的 7CT-3SNA 粉末，平均粒径为 30-50 nm，表明具有良好的烧结活性。拉曼光谱中约 800 cm ^-1处的新的窄有序带表明 7CT-3SNA 固溶体的 B 位点具有高有序度。与固相反应法和共沉淀法相比，现有方法制备的 0.7CT-0.3SNA 陶瓷具有更低的煅烧温度、相似的ε _r值和改进的Q  ×  f值。ε的最佳微波介电性能_r  = 43.54，Q  ×  f  = 54375 GHz，τ _f  = -6.3 × 10 ^-6 /°C 是从溶胶-凝胶自动燃烧过程中获得的 CTSA 陶瓷。因此，在该研究中制备的7CT-3SNA陶瓷是潜在的电介质材料对于微波应用，表明溶胶-凝胶自燃烧方法是用于的CaTiO的制造中的良好的替代策略₃ -LnAlO _3个陶瓷。