Low-temperature firing and microwave dielectric properties of Ca[(Li1/3Nb2/3)0.8Ti0.2]O3-δ ceramics with ZnB2O4 glass addition

Low-temperature sintered Ca[(Li(1/3)Nb(2/3))(0.8)Ti(0.2)]O(3-delta) microwave dielectric ceramics with ZnB(2)O(4) glass (ZBG) addition were prepared by the conventional solid state reaction method. The sintering behavior, microstructure, and microwave dielectric properties of Ca[(Li(1/3)Nb(2/3))(0.8)Ti(0.2)]O(3-delta) ceramics with ZBG addition were investigated. The ZBG addition lowered the densified temperature of Ca[(Li(1/3)Nb(2/3))(0.8)Ti(0.2)]O(3-delta) ceramics from 1150 degrees C to 940 degrees C. The dielectric constants of Ca[(Li(1/3)Nb(2/3))(0.8)Ti(0.2)]O(3-delta) ceramics decreased from 40 to 34 and the temperature coefficient of resonant frequency (tau(f)) changed gradually from +12.7 to -25.7 ppm/degrees C as ZBG addition increased from 0 to 8 wt%. The Q(f) values increased greatly from 20,500 GHz of pure Ca[(Li(1/3)Nb(2/3))(0.8)Ti(0.2)]O(3-delta) to 26,900 GHz when 5 wt% ZBG was added. Ca[(Li(1/3)Nb(2/3))(0.8)Ti(0.2)]O(3-delta) ceramics with 8 wt% ZBG addition sintered at 940 degrees C show good microwave dielectric properties with epsilon(r)similar to 32.5, Q(f)similar to 20,600 GHz, and tau(f)similar to-25.7 ppm/degrees C. The relationship between dielectric properties and microstructure was also discussed.