Temperature stable high-Q microwave dielectric ceramics in (1-x)BaTi4O9-xBaZn2Ti4O11 system

The microwave dielectric properties of (1 - x)BaTi4O9-xBaZn(2)Ti(4)O(11) ceramics were investigated by solid-state reaction technique for obtaining high-Q dielectric ceramics in BaO-ZnO-TiO2 system. And they were strongly determined by the chemical composition. As x was increased from 0.05 to 0.50, BaZn2Ti4O11 phase formed more and more. Therefore, the epsilon(r) decreased from 37.3 to 32.8 and the Q x f values first raised from 45,300 GHz to 60,600 GHz (x = 0.30) and then started to decline to 58,700 GHz (x = 0.40), and the tau(f) values varied gradually from 12 ppm/degrees C to 13 ppm/degrees C. 0.7BaTi(4)O(9)-0.3BaZn(2)Ti(4)O(11) ceramics sintered at 1240 degrees C for 3 h had excellent comprehensive microwave dielectric properties: epsilon(r) = 34.2, Q x f = 60,600 GHz and tau(f) = -2 ppm/degrees C. (C) 2011 Elsevier B.V. All rights reserved.