Microwave dielectric properties of (Ca1−xZnx)2P2O7

The phase evolution, sintering behaviour and microwave dielectric properties of mixed pyrophosphates (Ca1-xZnx)2P2O7 (x = 0.1-0.9) were investigated. Samples with x = 0.1-0.4 exhibit mixed phases of CaZnP2O7 and beta-Ca2P2O7, and the samples with x = 0.6-0.9 exhibit mixed phases of CaZnP2O7 and Zn2P2O7. A single-phase composition of CaZnP2O7 could be formed when x = 0.5. The mixed pyrophosphates (Ca1-xZnx)2P2O7 (x = 0.1-0.9) exhibit low sintering temperature (up to 900 C), low relative permittivity ( < 9), high Qf value and negative temperature coefficient of resonant frequency. Maximum Qf value of 63130 GHz could be obtained for CaZnP2O7 sintered at 900 C /2 h. Its dielectric constant and tauf value are 7.56 and -82 ppm/C, respectively. 6 refs.