Preparation and microwave dielectric properties of Li 3 (Mg 0.92 Zn 0.08 ) 2 NbO 6 –Ba 3 (VO 4 ) 2 composite ceramics for LTCC applications

Abstract In this work, the (1 − x )Li 3 (Mg 0.92 Zn 0.08 ) 2 NbO 6 – x Ba 3 (VO 4 ) 2 ( x = 0.1–0.35) ceramics were prepared via a conventional solid state reaction route. The phase composition, microstructure and microwave dielectric properties were investigated by an X-ray diffractometer (XRD), a scanning electron microscope and a network analyzer. The XRD results indicated that the Li 3 (Mg 0.92 Zn 0.08 ) 2 NbO 6 and Ba 3 (VO 4 ) 2 phases could well coexist without forming any secondary phases. The dielectric constant ( ϵ r ) and quality factor ( Q × f ) values of the Li 3 (Mg 0.92 Zn 0.08 ) 2 NbO 6 ceramic decreased with the addition of Ba 3 (VO 4 ) 2 phase, however its temperature coefficient of resonant frequency ( τ f ) value was improved significantly. Excellent microwave dielectric properties of ϵ r ∼ 16.3, Q × f ∼ 50,084 GHz (at 8.64 GHz) and τ f ∼ 1.5 ppm/°C were achieved for the x = 0.3 sample when sintered at 950 °C for 4 h. The chemical compatibility with Ag electrode indicated that the 0.7Li 3 (Mg 0.92 Zn 0.08 ) 2 NbO 6 –0.3Ba 3 (VO 4 ) 2 composite ceramic would be a promising material for the low temperature cofired ceramic applications.