Effect of Mg/B ratio and Sr2+ substitution for Mg2+ on the sintering, phase composition and microwave dielectric properties of Mg3B2O6 ceramics. Issue 16 (November 2020)

• Record Type: Journal Article
• Authors: Gu, Yong-jun; Ding, Xian-bing; Hu, Wei; Huang, Jin-liang; Li, Qian; Li, Li-hua; Li, Xin-li; Yang, Xing-hua; Chen, Min; Kim, Bok-hee
• Is Part Of: Ceramics international. Volume 46:Issue 16(2020)Part A
• Page Start: 25888
• Page End: 25894
• Publication Date: 2020-11
• Subjects: Microwave dielectric ceramics -- Dielectric property -- Sintering -- Mg3B2O6; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2020.07.073
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Mg3 B2 O6 is a typical microwave dielectric ceramic with a high Q f value, but the pure Mg3 B2 O6 ceramic is difficult to be obtained due to the volatilization of B2 O3 resulting from the high temperature during the fabrication process. We reveal the effects of Mg/B ratio and Sr 2+ substitution for Mg 2+ on the phase composition, sintering behavior, microstructure, and microwave dielectric properties of Mg3 B2 O6 . The pure Mg3 B2 O6 ceramic can be obtained with Mg/B ratio equal to 1.2. Proper excessive free-MgO is benefit to the improvement of Q f value of Mg3 B2 O6, while it is detrimental to the densification of Mg3 B2 O6 . No second phase was detected in the Sr 2+ substituted Mg3 B2 O6 and excellent microwave dielectric properties (εr = 6.9, Q f = 110820 GHz, and τ f = −32.4 ppm/°C at 12.8 GHz) were obtained in the (Mg0.998 Sr0.002 )3 B2 O6 ( x = 0.2 mol.%) ceramic sample sintered at 1250 °C for 3h, making it a hopeful candidate for wireless communications. These results bring forward the underlying insights needed to direct the design of microwave dielectric ceramics with high Q f values for personal communication applications.