Modulation of microwave dielectric properties in melilite-structured SrREGa3O7 (RE = La, Pr) ceramics. Issue 5 (1st March 2022)

• Record Type: Journal Article
• Authors: Ma, Jinyan; Chen, Junqi; Xiang, Huaicheng; Li, Jie; Tang, Ying; Fang, Liang
• Is Part Of: Ceramics international. Volume 48:Issue 5(2022)
• Page Start: 6218
• Page End: 6224
• Publication Date: 2022-03-01
• Subjects: Gallium-based melilite -- Microwave dielectric properties -- Ion dielectric polarizability -- "Rattling" effect -- Bond valence; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2021.11.162
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Gallium-based SrREGa3 O7 (RE = La, Pr) melilite ceramics were prepared and selected to modify their microwave dielectric properties. Sintered at 1425 °C for 6 h, SrLaGa3 O7 (SLGO) and SrPrGa3 O7 (SPGO) ceramics exhibited high relative densities of 98.33 and 95.23%, low ε r values of 11.8 and 10.9, Q×f values of 32, 500 GHz (at 12.1 GHz) and 26, 400 GHz (at 12.7 GHz), negative τ f values of −32 and −54 ppm/°C. As a compensator, CaTiO3 can tune the τ f values of SLGO and SPGO to near zero (+2 and −4 ppm/°C). In SrREGa3 O7 melilite ceramics, the ε r and τ 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 SrREGa3 O7 (RE = La, Pr) microwave dielectric ceramics have also been comprehensively reported.