Microwave dielectric properties and low temperature sintering of Li ₂Zn(Ti_1-xSn_x)₃O₈ (x ≤ 0.20) ceramics with B₂O₃-CuO addition

In the present work, the influence of Sn substitution for Ti on the phase composition and microwave dielectric properties of the Li₂Zn(Ti _1-xSnx)₃O₈ (x ≤ 0.20) ceramics was studied. It was found that the Sn did not occupy the Ti site in the Li ₂Zn(Ti_1-xSn_x)₃O₈ system but existed in the form of SnO₂ as a secondary phase. With the increase of Sn amount, the best microwave dielectric properties with ε_r = 23.3, Q × f = 71,000 GHz and TCF = -21.7 ppm/ C were obtained in the Li₂Zn(Ti_0.9Sn_0.1) ₃O₈ ceramic sintered at 1,120 C. The sintering temperature of Li₂Zn(Ti_0.9Sn_0.1)₃O₈ ceramic can be can effectively lowered to below 960 C by the addition of 0.4B₂O₃-0.6CuO and this materials is chemically compatible with silver. This makes the Li₂Zn(Ti_1-xSn _x)₃O₈ ceramics good candidates for low temperature co-fired ceramics technology.