Microwave dielectric properties of a low firing and temperature stable lithium magnesium tungstate (Li4MgWO6) ceramic with a rock-salt variant structure.

The Li 4 MgWO 6 ceramic was synthesized by the conventional solid-state reaction method, and its sintering behavior and microwave dielectric properties were studied for the first time. The XRD patterns and structural refinements indicated that Li 4 MgWO 6 formed an orthorhombic phase at temperatures above 900 °C, and TEM analyses confirmed the ordered and layered rock-salt superstructures for the orthorhombic Li 4 MgWO 6. The SEM photographs and relative density curve showed that the sample sintered at 950 °C had the highest densification. When sintered at 950 °C in a WO 3 -rich atmosphere for 4 h, Li 4 MgWO 6 had the following optimum properties: ε r = 15.06±0.33, Q × f = 28,300±600 GHz (f = 10.1 GHz), and τ f = 0.9±3.4 ppm/°C. Compared with other reported low permittivity compounds, Li 4 MgWO 6 shows more potential for the Low-Temperature Cofired Ceramics (LTCC) substrate materials due to its intrinsic low sintering temperature, novel temperature stability, and relatively low dielectric loss. [ABSTRACT FROM AUTHOR]