Microwave dielectric properties of Ca[(Li1/3Nb2/3)1-xTix]O3-δ-Lithium Magnesium Zinc borosilicate ceramic-glass composite for LTCC applications

The Ca[(Li_1/3Nb_2/3)_1-xTi_x]O_3-delta (x=0.2 and 0.25) (CLNT) ceramics with Lithium Magnesium Zinc Borosilicate (LMZBS) glasses were prepared by conventional solid state ceramic route. The crystal structure and microstructure of the glass added and sintered CLNT ceramics were studied using X-ray diffractometer and Scanning electron microscope. The addition of LMZBS glasses improved the densification and lowered the sintering temperature of CLNT ceramics from 1175degC to 900degC without degrading the microwave dielectric properties. The tau_f value is tuned by increasing the titanium content in the Ca[(Li_1/3Nb_2/3)_0.8Ti_0.2]O_3-delta ceramics. The Ca[(Li_1/3Nb_2/3)_0.75Ti_0.25]O_3-delta ceramics with 12 wt% of LMZBS and sintered at 900degC/4h has epsiv_tau=28.52, Q_uxf =11000 GHz and tau_f = -3 ppm/degC. This results shows that the Ca[(Li_1/3Nb_2/3)_0.75Ti_0.25]O_3-delta ceramics with suitable amount of LMZBS glass addition can find application in LTCC based devices.