Microwave dielectric properties of 5Li2O-(Nb1−xMx)2O5-5TiO2 (M=Mo, W, 0<x<0.2) ceramics
5Li<sub>2</sub>O-(Nb<sub>1-x</sub>M<sub>x</sub>)<sub>2</sub>O<sub>5</sub>-5TiO<sub>2</sub> (M=Mo, W, 0<;x<;0.2) ceramics were prepared via solid state method. The phase composition and microwave dielectric properties were studied. There is no Mo-related phase observed even 20 mol% Mo is doped. However, the Li<sub>2</sub>WO<sub>4</sub> is clearly detected from XRD results for 5Li<sub>2</sub>O-(Nb<sub>1-x</sub>W<sub>x</sub>)<sub>2</sub>O<sub>5</sub>-5TiO<sub>2</sub> (x>0.05). Both Mo and W can lower the sintering temperature. The doped ceramics can be sintered at 1000°C which is 100°C lower than the sintering temperature of pure 5Li<sub>2</sub>O-(Nb<sub>1-x</sub>M<sub>x</sub>)<sub>2</sub>O<sub>5</sub>-5TiO<sub>2</sub> ceramic. The relative permittivity and Q×f value decrease gradually with increasing doping. And best microwave dielectric properties with a relative permittivity of 29 and a quality factor (Q×f) ~7,000 GHz (at 6.5 GHz) is achieved when 5Li<sub>2</sub>O-(Nb<sub>0.95</sub>Mo<sub>0.05</sub>)<sub>2</sub>O<sub>5</sub>-5TiO<sub>2</sub> is sintered at 1000°C/2h.