Influence of W substitution on crystal structure, phase evolution and microwave dielectric properties of (NaBi)MoO ceramics with low sintering temperature.

In this work, the (NaBi)(MoW)O (x = 0.0, 0.5 and 1.0) ceramics were prepared via solid state reaction method. All the samples can be well densified at sintering temperature about 720 °C. Dense and homogeneous microstructure with grain size lying between 28 μm can be observed from scanning electron microscopy (SEM). Microwave dielectric permittivity of the (NaBi)(MoW)O ceramic was found to be temperature-independent in a wide range between 25120 °C with a temperature coefficient of frequency (TCF) ~-6 ppm/°C, a permittivity ~28.9, and Qf values 12,00014,000 GHz. Crystal structure was refined using Rietveld method and lattice parameters are a = b = 5.281 (5) Å and c = 11.550 (6) Å with a space group I 4/a (88). The (NaBi)(MoW)O ceramics might be good candidate for low temperature co-fired ceramics (LTCC) technology.