Influence of ionic substitution on the microwave dielectric properties of Li^sub 2^Mg^sub 0.95^A^sub 0.05^TiO^sub 4^ (A=Ni, Co, Mn, Zn) ceramics

• Published in: Journal of materials science. Materials in electronics 2017-06, Vol.28 (11), p.8304
• Main Authors: Du, H, Li, C C, Liu, F L, Zhang, Y W, Cui, L F, Bi, J X, Wu, H T
• Format: Article
• Language: English
• Subjects: Ceramics; Cobalt; Dielectric properties; Manganese; Nickel; Resonant frequencies; Sintering; Zinc
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-017-6544-z

The rock-salt structured Li2Mg0.95A0.05TiO4 (A=Ni, Co, Mn, Zn) ceramics were prepared by the conventional solid-state method. The effects of different bivalent ions on the phase compositions, microstructure and microwave dielectric properties were investigated systematically. All the sintered samples exhibited a single phase with the space group of Fm-3m. The dielectric constants of Li2Mg0.95A0.05TiO4 ceramics were affected by the apparent densities and the dielectric polarizabilities. The Q·f values of Li2Mg0.95Co0.05TiO4 and Li2Mg0.95Zn0.05TiO4 ceramics were improved to ~110,000 GHz when the samples were sintered at 1350°C. In addition, the temperature coefficient of resonant frequency showed no significant changes with the ionic substitutions. Typically, the Li2Mg0.95Co0.05TiO4 ceramics exhibited excellent microwave dielectric properties of ε r=15.74, Q·f=111,700 GHz and τf = -4.78 ppm/°C at 1350°C. The Li2Mg0.95Zn0.05TiO4 specimens sintered at the same temperature also possessed similar dielectric properties with ε r = 16.07, Q·f=111,300 GHz and τf = -8.02 ppm/°C.