Crystal structure, electric and microwave dielectric properties of La2Mg(Mg1/3Sb2/3)O6 novel double-perovskite with non-stoichiometric 1:1 cationic ordering

作者：Yang, Li; Yang, Xiaoyan; Fang, Weishuang; Deng, Sihao; He, Lunhua; Liu, Laijun; Fernandez-Carrion, Alberto J.; Kuang, Xiaojun

来源：Journal of the European Ceramic Society, 2023, 43(3): 1000-1008.

DOI：10.1016/j.jeurceramsoc.2022.10.033

• Complex double perovskite
• Neutron powder diffraction
• Dielectric properties
• Cation ordering

In this contribution, the novel double-perovskite La2Mg(Mg1/3Sb2/3)O6 has been successfully prepared by solid-state reaction method, and its structure has been determined for the first time by a combination of X-ray and neutron powder diffraction data analysis. The novel material exhibits a thermal expansion of-9.1 ppm/degrees C and a large optical band gap (4.23 eV). The complex impedance data analysis indicates that La2Mg(Mg1/3Sb2/3)O6 features a Debye-like behaviour, with a bulk conductivity, & sigma;b, varying between 10-7-10-4 S ?cm-1 within 500-900 degrees C temperature range, and activation energy (Ea) of -1.36 eV. In addition, the microwave dielectric properties of La2Mg(Mg1/3Sb2/3)O6 sintered at 1625 degrees C display optimized quality factor (Qxf) of -28,700 GHz (f = 9.65 GHz), a dielectric constant (& epsilon;r) of -20.2 and temperature coefficient of the resonant frequency (of) of - 89 ppm/degrees C. This work widen the reduced number of A3+( ) B2+ 2/3B5+ O3 compounds explored so far. 1/3

• 单位
  桂林理工大学; 中国科学院