Structure and microwave dielectric properties of the Li2O-MgO-TiO2 systems

In this paper, Li2O-MgO-TiO2 (1:x:1, x = 1, 2, 3, 4 and 5) ceramic systems were prepared by solid-state reaction sintering. The effects of extra magnesium content on the phase evolution, crystal structure and microwave dielectric characteristics of Li2O-MgO-TiO2 ceramics were systematically investigated. The Li2MgTi3O8, Li2Mg3TiO6, and (Li2TiO3)(10.667) coexisted at x = 1 and 2. When x augmented to 3, the pure Li2Mg3TiO6-like phase was obtained with the increase of magnesium content. All specimens showed porous structure and clear grain boundaries. The microwave dielectric characteristics are extraordinary dependent on chemical component and densification. The Li2O-4MgO-TiO2 ceramics sintered at 1350 degrees C possessed preeminent comprehensive performance of epsilon(r) = 13.95, Q x f = 119,072 GHz and tau(f) = - 40.9 ppm/degrees C.

Automated summary

Li2O-MgO-TiO2 ceramics with different magnesium contents were prepared, and the phase evolution, crystal structure, and microwave dielectric characteristics were investigated. It was found that Li2MgTi3O8, Li2Mg3TiO6, and (Li2TiO3)(10.667) coexisted at x = 1 and 2, while the pure Li2Mg3TiO6-like phase was obtained when x was increased to 3. The ceramics displayed porous structure and clear grain boundaries. The microwave dielectric characteristics were highly dependent on the chemical composition and densification. The Li2O-4MgO-TiO2 ceramics sintered at 1350 degrees C exhibited excellent comprehensive performance with ε(r) = 13.95, Q x f = 119,072 GHz, and τ(f) = - 40.9 ppm/°C.