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

• Study the microwave dielectric properties and microstructure of Li2(Mg1–xAx)Ti3O8.
• Li2(Mg0.96Zn0.04)Ti3O8 possesses a excellent dielectric properties.
• This is a unique potential for low-loss microwave applications.

The microstructure and microwave dielectric properties of Li2(Mg1–xAx)Ti3O8 (A2+ = 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 × 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(Mg1–xAx)Ti3O8 ceramics are also discussed. The specimen comprising Li2(Mg0.96Zn0.04)Ti3O8 possesses a moderate εr of 28.7, a very small τf of –3.18 ppm/°C, and an extremely high Q × f of 151,200 GHz, demonstrating a unique potential for low-loss microwave applications.