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

作者：Ma, Jinyan; Chen, Junqi; Tang, Ying^*; Lia, Jie^*; Fang, Weishuang; Dai, Yimin; Fang, Liang^*

来源：Journal of the European Ceramic Society, 2022, 42(2): 478-484.

DOI：10.1016/j.jeurceramsoc.2021.10.005

• Low epsilon r
• microwave dielectric properties
• P-V-L theory

Two novel low-E r microwave dielectric ceramics AGa(4)O(7) (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: epsilon(r) = 9.1, Q x f = 40 600 GHz (f = 12.4 GHz), and tau(f) = -86.3 ppm degrees C-1; SGO: epsilon(r) = 9.2, Q x f = 62 400 GHz (f = 14.6 GHz), and tau(f) = -63.4 ppm degrees C-1) are obtained. The P-VL-chemical bond theory indicated that Ga-O bonds play a role in affecting the epsilon(r) and Q x f values. The tau(f) of AGa(4)O(7) (A = Ca, Sr) had adjusted close to zero (0.93CGO-0.07CaTiO(3): epsilon(r) = 11.3, Q x f = 31,043 GHz, and tau(f) = 3.97 ppm degrees C-1; 0.82SGO-0.18LiCa(2)Mg(2)V(3)O(12): epsilon(r) = 11.8, Q x f = 55,564 GHz, and tau(f) = 5.62 ppm degrees C-1).

• 单位
  y; 桂林理工大学; 广西大学