High Q Microwave Dielectric Ceramics in the Li2(Zn1−xAx)Ti3O8 (A = Mg, Co; x = 0.02-0.1) System

Using a conventional solid‐state reaction, followed by sintering at 1080°C–1200°C Li2(Zn1−xAx)Ti3O8 (A = Mg, Co and x = 0.02–0.1) ceramic system with >96% density were prepared. The XRD patterns of the sintered samples revealed single‐phase formation with a cubic crystal symmetry. The molecular volume shows good linear relationship with x value. The microwave dielectric properties of Li2(Zn1−xAx)Ti3O8 ceramics exhibited a significant dependence on the x value and to some extent on the morphology of the specimens. The Li2(Zn0.94Mg0.06)Ti3O8 ceramics possess εr = 26.1, Q × f = 150 000 GHz, and τf = −13.9 ppm/°C, and Li2(Zn0.92Co0.08)Ti3O8 ceramics show εr = 24.7, Q × f = 140 000 GHz, and τf = −13.4 ppm/°C, respectively. It indicates a substantial increase in the Q × f in comparison with that of pure Li2ZnTi3O8. The microwave dielectric properties of these partially substituted ceramics are reported for the first time.