Study Of The Fabrication And Dielectric Properties Of ZnO-TiO₂Dielectric Ceramics

One of the key technologies in the particle accelerator is Asymmetric Pulse Form Line Technology. In recent years, it is one of attractive research areas that take ceramics medium as solid medium for their superior performance and advantages of dielectric ceramics. The demands of dielectric ceramic includes a certain dielectric constant, low dielectric loss and high breakdown strength. Consequently, it is significant to explore new material system. The objective of this paper has explored and prepared the ZnO-TiO2ceramic system and dielectric properties, ensured the process technology of porcelain, with prospect of application to the Asymmetric Pulse Form Line in devicesThis paper take ZnO-TiO2system (Zinc Titanate or ZT as shortly) as object of study, prepare two kinds of composite ceramics including Zn2TiO4-xTiO2and Zn2Ti04-yZnO (x=0.2,0.4,0.6,0.8,1;y=0,0.1,0.2) in traditional solid reaction method. The data and analysis manifest that the range of relative dielectric constant εr is from19to31in measure frequency of1kHz at room temperature. Additionally, the dielectric constants are less variable in extra electric field lower than3kV/mm. Additional phase recognized as Zn2Ti3O8has been found in Zn2TiO4-xTiO2, and the dielectric loss are lower than7X10-3. With the rise of x, the stability of dielectric constant with frequency and temperature deteriorate. The dielectric loss of Zn2TiO4-yZnO are lower than2X10-2. With the decrease of the y, dielectric relaxation phenomenon is abate, the stability of dielectric constant on frequency and temperature improves. Impedance analysis show that grain activation energy Eg is lower than that in grain boundary Egb in various components of the zinc titanate ceramic. When x≈0.6, Egb reach a peak about1.39eV, and the conductive leakage at this component is low, about2X10-9A in extra electric field5kV/mm.This work has also prepared the dimensional size zinc titanate porcelain. In order to compare with synthesis process and performance of zinc titanate porcelain, magnesium titanate porcelain has also been prepared and studied with raw material on selling in market. The study manifest that appropriate zinc titanate porcelain sintering temperature is approximate1160℃, higher than that of small zinc titanate samples, and lower than that of magnesium titanate porcelain is approximate1260℃. The dielectric properties of zinc porcelain are better than that of magnesium titanate, including more stable dielectric constant with frequency, lower dielectric loss and higher breakdown strength. The breakdown strength distributions are similar with mechanical strength distribution in two different kinds of porcelain, which can be obeyed to statistical distribution regularity. The highest breakdown strength of Zn2TiO4ceramic is approximate14.5kV/mm. It’s the micro crack that dominates the dielectric and mechanical properties. Additionally, grain size and pores are another factors deteriorate properties of porcelains. The sintering activation energy is approximate275.6kJ/mol, which calculated roughly from the grain growth dynamics analysis of zinc titanate.