Optimization of dielectric constant temperature coefficient of pyrochlores containing bismuth
(1. School of Technical Physics, Xidian University, Xi'an 710071, China;
2. School of Electrical Engineering, Xi'an Jiaotong University, Xi'an 710049, China;
3. The First Department, The Second Artillery Institute of Engineering,
Xi'an 710025, China)
2. School of Electrical Engineering, Xi'an Jiaotong University, Xi'an 710049, China;
3. The First Department, The Second Artillery Institute of Engineering,
Xi'an 710025, China)
Abstract: The Bi2O3-ZnO-Nb2O5(BZN)-based ceramic samples were prepared according to the optimum composition of (Bi3xZn2-3x)(ZnxNb2-x)O7 by solid state reaction. The BZN ceramic structure and the dielectric properties were explored via X-ray diffractometer(XRD), differential thermal analysis(DTA), scanning electron microscope(SEM), and HP4275A impedance analysis. The amphoteric surface active agent with alcohol amine double nature is introduced when the raw materials are mixed and ground. The anatase titania doped BZN-based ceramics was also investigated. Either doping the anatase TiO2 or adding the surface active agent or both of them can widen sintering temperature range which satisfies the zero temperature coefficient (0±30×10-6/℃) of the BZN ceramics. And these BZN ceramics with diphasic pyrochlore structure possess excellent dielectric properties.
Key words: Bi2O3-ZnO-Nb2O5 ceramic; phase transformation; dielectric properties