Microwave dielectric properties of (Ca1−xZnx)2P2O7

The phase evolution, sintering behavior and microwave dielectric properties of mixed pyrophosphates (Ca1−xZnx)2P2O7 (x=0.1-0.9) were investigated in this paper. The results show that samples with x=0.1-0.4 exhibit mixture phases of CaZnP2O7 and β-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 (≤900 °C), low relative permittivity (<9), high Q×f value and negative temperature coefficient of resonant frequency. Maximum Q×f value of 63,130 GHz could be obtained for CaZnP2O7 sintered at 900 °C/2 h. Its dielectric constant and τf value are 7.56 and −82 ppm/°C, respectively.