Low loss and temperature stable microwave dielectrics using Li2(Mg1-xAx)Ti3O8 (A2+ = Zn, Co; x=0.02-0.1) ceramics

The microstructure and microwave dielectric properties of Li-2(Mg(1-x)A(x))Ti3O8 (A(2+) = Zn, Co and x = 0.02-0.1) ceramics are investigated. The forming of solid solutions was confirmed by XRD analysis, EDX analysis, and the measured lattice parameters. It was found that a small amount of Zn-or Co-substitution for Mg had a significant effect on the Q x f of the ceramics, increasing its value by up to 260% compared to that of pure Li2MgTi3O8. The relationships between ionic polarizability, packing fraction, and microwave dielectric properties in Li2(Mg(1-x)A(x))Ti3O8 ceramics are also discussed. The specimen comprising Li2(Mg0.96Zn0.04)Ti3O8 possesses a moderate epsilon(r) of 28.7, a very small tau(f) of -3.18 ppm/degrees C, and an extremely high Q x f of 151,200 GHz, demonstrating a unique potential for low-loss microwave applications. (C) 2014 Elsevier B.V. All rights reserved.