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

Highlights: • Microwave properties of ϵ{sub r} ∼ 16.3, Q × f ∼ 50,084 GHz and τ{sub f} ∼ 1.5 ppm/°C are achieved. • The τ{sub f} value of the LMZN ceramic can be adjusted to near zero by adding BV. • The LMZN–BV composite ceramic can be well sintered at a relatively low temperature. • The composite ceramic has a good chemical compatibility with Ag electrode. - Abstract: In this work, the (1 − x)Li{sub 3}(Mg{sub 0.92}Zn{sub 0.08}){sub 2}NbO{sub 6}–xBa{sub 3}(VO{sub 4}){sub 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{sub 3}(Mg{sub 0.92}Zn{sub 0.08}){sub 2}NbO{sub 6} and Ba{sub 3}(VO{sub 4}){sub 2} phases could well coexist without forming any secondary phases. The dielectric constant (ϵ{sub r}) and quality factor (Q × f) values of the Li{sub 3}(Mg{sub 0.92}Zn{sub 0.08}){sub 2}NbO{sub 6} ceramic decreased with the addition of Ba{sub 3}(VO{sub 4}){sub 2} phase, however its temperature coefficient of resonant frequency (τ{sub f}) value was improved significantly. Excellent microwave dielectric properties of ϵ{sub r} ∼ 16.3, Qmore » × f ∼ 50,084 GHz (at 8.64 GHz) and τ{sub 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{sub 3}(Mg{sub 0.92}Zn{sub 0.08}){sub 2}NbO{sub 6}–0.3Ba{sub 3}(VO{sub 4}){sub 2} composite ceramic would be a promising material for the low temperature cofired ceramic applications.« less