Investigation On ZnTi?Zr?Nb₂O₈-based Microwave Dielectric Ceramics

The development of high quality microwave dielectric ceramic is a key point for the miniaturization and selectivity of passive device, and owing to the need of these, a breaking through in the ??Qf value and ?f is most urgent nowadays. In this letter, ZnTiNb2O8 based and ZnZrNb2O8 based microwave dielectric ceramic were doped for a better microwave properties, the crystal structure?phase constitution and microwave properties were investigated systematically. In addition, some microwave dielectric ceramic materials with good properties were presented.Firstly, ixiolite structure ZnTiNb2O8 was investigated by doping divalent cation. We choose Ni2+(0.69?, CN=6)cation which has a similar ionic radius with Zn2+(0.74?, CN=6)cation and Ca2+(1.00?, CN=6)cation which has a dissimilar ionic radius with Zn2+ as the doping ion. The phase constitution and the variation of crystal structure were investigated with the increasing doping content, and the relationship between that above and microwave dielectric properties were built. In addition, temperature stable ceramic materials were presented.Secondly, CaCO3?TiO2 and SnO2 were doped in ZnTiNb2O8 together for a improvement in dielectric properties. The content of Ca2+ cation were regarded as a variate. And the relationship between that above and microwave dielectric properties were built. What is more, a microwave dielectric ceramic material with good properties was got.Finally, monoclinal structure ZnZrNb2O8 based microwave dielectric ceramic with a small amount of doping divalent ions were investigated to explore the effect of different doping ion on crystal structure and phase constitution of the system. Considering the microwave performance of each materials, Mg2+ cation was selected as doped ions to investigate deeply. We choose x = 0.1 to x = 0.8 as the doping amount of Zn1-xMgxZrNb2O8 material, investigated the effect of doping content on phase constitution and crystal structure. Considering its excellent microwave performance, we select Zn0.5Mg0.5ZrNb2O8 materials to investigated deeply, regarding sintering temperature as the variables. Crystal cell parameters, bond strength, packing fraction were used to represent the variation of crystal structure to analyzes the key factors influencing the performances of microwave ZnZrNb2O8 based material. In addition, ZnZrNb2O8 based microwave dielectric ceramic material with good properties was got.