Modulation of microwave dielectric properties in melilite-structured SrREGa3O7 (RE = La, Pr) ceramics

作者：Ma, Jinyan; Chen, Junqi; Xiang, Huaicheng^*; Li, Jie; Tang, Ying; Fang, Liang^*

来源：Ceramics International, 2022, 48(5): 6218-6224.

DOI：10.1016/j.ceramint.2021.11.162

• Gallium-based melilite
• Microwave dielectric properties
• Ion dielectric polarizability
• "Rattling" effect
• Bond valence

Gallium-based SrREGa3O7 (RE = La, Pr) melilite ceramics were prepared and selected to modify their microwave dielectric properties. Sintered at 1425 degrees C for 6 h, SrLaGa3O7 (SLGO) and SrPrGa3O7 (SPGO) ceramics exhibited high relative densities of 98.33 and 95.23%, low epsilon(r) values of 11.8 and 10.9, Qxf values of 32,500 GHz (at 12.1 GHz) and 26,400 GHz (at 12.7 GHz), negative tau(f) values of -32 and -54 ppm/degrees C. As a compensator, CaTiO3 can tune the tau(f) values of SLGO and SPGO to near zero (+2 and -4 ppm/degrees C). In SrREGa3O7 melilite ceramics, the epsilon(r) and tau(f) values are mainly dependent on ionic polarizability, crystal structure and the "rattling" effect. The micromorphology, XPS, Raman spectrum and A-site bond valence (V-RE) of SrREGa3O7 (RE = La, Pr) microwave dielectric ceramics have also been comprehensively reported.

• 单位
  广西大学; 桂林理工大学