Sintering characteristics, crystal structure, and microwave dielectric properties of Li2(Mg0.9A0.1)4TiO7 (A = Co2+, Ni2+, Mg2+, Zn2+, Ca2+)
- 47 Downloads
The Li2(Mg0.9A0.1)4TiO7 (A = Co2+, Ni2+, Mg2+, Zn2+, Ca2+) ceramics were prepared by the conventional solid-state reaction method. A series of Li2(Mg0.9A0.1)4TiO7 ceramics were investigated in regard to the sintering temperatures, crystal structures and dielectric properties. The Li2(Mg0.9A0.1)4TiO7 ceramic exhibited a single phase of Li2Mg4TiO7, and the Rietveld refinement was used to analyze the crystal structure. The Li2(Mg0.9Ca0.1)4TiO7 ceramics could be sintered below 1350 °C with high densities, high dielectric constants and near zero τf values. The maximum Q·f value of Li2(Mg0.9Zn0.1)4TiO7 was higher than that of Li2(Mg0.9A0.1)4TiO7 (A = Co2+, Ni2+, Mg2+, Ca2+). The optimum microwave dielectric properties of εr = 14.77, a high Q·f value of 162,200 GHz and τf = − 4.30 ppm/°C were achieved in Li2(Mg0.9Zn0.1)4TiO7 ceramic sintered at 1500 °C. In addition, Li2(Mg0.9Ca0.1)4TiO7 ceramic sintered at 1300 °C exhibited the suitable dielectric properties with a high εr value of 15.79, Q·f = 100,300 GHz and a near zero τf value of − 1.43 ppm/°C.
This work was supported by China Postdoctoral Science Foundation (2017M612341). The authors are thankful to the help of Professor Zhenxing Yue and postdoctoral Jie Zhang on the measurement of microwave properties in Tsinghua University.
- 3.I.M. Reaney, D. Iddles, J. Am. Ceram. Soc. 89, 2063 (2006)Google Scholar
- 7.G.G. Yao, P. Liu, H.W. Zhang, J. Mater. Sci.: Mater. Electron. 24, 1128 (2013)Google Scholar
- 16.H.T. Chen, B. Tang, X. Guo et al., J. Mater. Sci.: Mater. Electron. 46, 1230 (2017)Google Scholar
- 21.R.D. Shannon, Am. Miner. 77, 94 (1992)Google Scholar