Effect of Zn0·17Nb0·33Ti0·5O2 on the Microwave Dielectric Properties of ZnTiNb2O8 Ceramics

An original (1-x)ZnTiNb2O8-xZn(0.17)Nb(0.33)Ti(0.5)O(2) (x = 0.35-0.75) composite ceramics were prepared by the traditional solid-state method. X-Ray diffraction and Raman spectroscopy results illustrated that only ZnTiNb2O8 and Zn0.17Nb0.33Ti0.5O2 were synthesized without any extra phase. The morphology and microstructures of the microwave dielectric ceramics were characterized by scanning electron microscopy and energy disperse spec-troscopy. The addition of Zn0.17Nb0.33Ti0.5O2 not only effectively adjusted the tau(f) of ZnTiNb2O8 matrix from-39.55 ppm/degrees C to 54.32 ppm/degrees C, but also significantly increased epsilon(r) from-39.55 ppm/degrees C to 54.32 ppm/degrees C. But the Q x f values deteriorated from 36,914 GHz to 21,077 GHz as x increased. The ceramic with near-zero tau(f)was synthesized at x = 0.55, meanwhile, 0.45ZnTiNb(2)O(8)-0.55Zn(0.17)Nb(0.33)Ti(0.5)O(2) ceramic sintered at 1200 degrees C possessed attractive microwave dielectric properties: epsilon(r) = 39.08 (6.2 GHz), Q x f = 31,384 GHz, and tau(f) =-6.45 ppm/degrees C.