Effect of LiF on microwave dielectric properties of nonstoichiometric Mg2SiO4 derived using deep eutectic solvents

• Published in: Journal of materials science. Materials in electronics 2023-03, Vol.34 (9), p.844, Article 844
• Main Authors: Zhang, Hao-jie, Li, Qian, Gu, Yong-jun, Li, Li-hua, Huang, Jin-liang, Kim, Bok-hee
• Format: Article
• Language: English
• Subjects: Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Choline; Densification; Dielectric properties; Internet of Things; Low temperature; Magnesium; Materials Science; Optical and Electronic Materials; Silicon dioxide; Sintering; Sintering (powder metallurgy); Solvents
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-023-10151-0

Nonstoichiometric Mg 2 SiO 4 ceramics with various Mg/Si ratios and doped with LiF were fabricated via the choline chloride-malonic acid deep eutectic solvent (DES) route. The secondary phases including MgO, MgSiO 3 , and SiO 2 were detected in the powder with an Mg/Si ratio of excess silicon after calcined at 1200 °C. The Q ×  f value of the as-fabricated Mg 2 SiO 4 ceramics was improved because LiF facilitates its densification. The ceramics have excellent properties despite of the presence of secondary phases. The optimum dielectric properties ( ε r  = 6.5, Q ×  f  = 118,000 GHz, τ f  = − 54.6 ppm/°C at 15 GHz) were obtained in the ceramics with an Mg/Si ratio of 1.6 sintered at 950 °C for 3 h. These results indicate that the Mg 2 SiO 4 ceramic prepared by DES route, which is eco-friendly and time-saving, could be a possible candidate for low temperature co-fired ceramic (LTCC) applications.