Chemical bond and microwave dielectric properties of two novel low-εr AGa4O7 (A = Ca, Sr) ceramics. Issue 2 (February 2022)

• Record Type: Journal Article
• Authors: Ma, Jinyan; Chen, Junqi; Tang, Ying; Li, Jie; Fang, Weishuang; Dai, Yimin; Fang, Liang
• Is Part Of: Journal of the European Ceramic Society. Volume 42:Issue 2(2022)
• Page Start: 478
• Page End: 484
• Publication Date: 2022-02
• Subjects: Low εr -- microwave dielectric properties -- PVL theory; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2021.10.005
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: Two novel low- εr microwave dielectric ceramics AGa4 O7 (A = Ca, Sr; called CGO and SGO, respectively) were analyzed by XRD, SEM, and Raman spectroscopy, showed the monoclinic structure with a C2/c space group. Encouraging microwave dielectric properties (CGO: εr = 9.1, Q × f = 40 600 GHz ( f = 12.4 GHz), and τ f = −86.3 ppm °C −1 ; SGO: εr = 9.2, Q × f = 62 400 GHz ( f = 14.6 GHz), and τ f = −63.4 ppm °C −1 ) are obtained. The PVL chemical bond theory indicated that GaO bonds play a role in affecting the εr and Q × f values. The τf of AGa4 O7 (A = Ca, Sr) had adjusted close to zero (0.93CGO-0.07CaTiO3 : εr = 11.3, Q × f = 31, 043 GHz, and τ f = 3.97 ppm °C −1 ; 0.82SGO-0.18LiCa2 Mg2 V3 O12： εr = 11.8, Q × f = 55, 564 GHz, and τ f = 5.62 ppm °C −1 ).