Low-temperature synthesis/densification and properties of Si2N2O prepared with Li2O additive

✍ Scribed by Qingfeng Tong; Jingyang Wang; Zhongping Li; Yanchun Zhou

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 418 KB
• Volume: 27
• Category: Article
• ISSN: 0955-2219
• DOI: 10.1016/j.jeurceramsoc.2007.04.004

✦ Synopsis

Dense Si 2 N 2 O was successfully synthesized using 2 mol% Li 2 O as an additive by a hot-pressing method at 1500 • C. Compared to other metal oxide additives, Li 2 O can significantly decrease the sintering temperature of Si 2 N 2 O, which is ascribed to the lower melting point of Li 2 O-SiO 2 and the formation of less viscous liquid phase. Increasing Li 2 O content has no apparent influence on the mechanical and dielectric properties of dense Si 2 N 2 O, which is due to the easy evaporation of Li 2 O at sintering temperature. The mechanical properties of Si 2 N 2 O with Li 2 O additive are comparable to those of Si 2 N 2 O synthesized with other additives. The as-prepared bulk Si 2 N 2 O with 2 mol% Li 2 O additive exhibits both low dielectric constant (6.17 at 1 MHz) and loss tangent (0.0008 at 1 MHz) and combines good mechanical performance, indicating it is a potential high-temperature structural/functional material.