Effects of LiF addition on the densification and microwave dielectric properties of LiInO2 ceramics. Issue 20 (15th October 2021)

• Record Type: Journal Article
• Authors: Chen, Junqi; Fang, Weishuang; Tang, Ying; jie Li, ; Fang, Liang
• Is Part Of: Ceramics international. Volume 47:Issue 20(2021)
• Page Start: 28960
• Page End: 28967
• Publication Date: 2021-10-15
• Subjects: Microwave dielectric properties -- Positive τf -- P–V-L chemical bond theory -- Dielectric spectroscopy; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2021.07.056
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Low-temperature co-fired ceramics (LTCC) LiInO2 + x wt% LiF ( x = 0, 1, 2, 3, 4, 5) was synthesized by a traditional solid-state reaction method. XRD, TEM, and SEM show that all specimens form a pure-phase tetragonal structure w ith a space group of I 41 /amd . The addition of LiF can effectively optimize the microstructure and improve the relative density of LiInO2 ceramics. As x value increased, the ε r increased from 9.6 to 13.6, Q×f increased from 39, 600 GHz to 52, 500 GHz, and all the specimens exhibit a positive τ f value at the range of 9.6–19.1 ppm/°C. The low- ε r and positive τ f in LiInO2 ceramics was investigated by bond valence and P–V-L chemical bond theory, indicating that it was closely related to the rattling effect of In and Li. The concentration of oxygen vacancies was studied by dielectric spectroscopy, indicating that doping LiF can compensate for the volatilization of Li during high temperature sintering. Notably, excellent microwave dielectric properties ( ε r ~ 13.6, Q×f = 52, 500 GHz, and τ f ~ 18.1 ppm/°C) were achieved in the LiInO2 + 3 wt% LiF sintered at 890 °C.