Study On Doping Effect Of Lead Zirconate Titanate Ferroelectric Ceramics

Pb(Zrx, Ti1-x)O3(abbreviated as PZT) ceramic is the binary solid solution of anti-ferroelectrics PbZrO3 and ferroelectrics PbTiO3. It is the typical ferroelectric crystal with the perovskite structure. There is a phase transition from high-temperature rhombic to low-temperature rhombic when Zr/Ti ratio is at about 95/5. PZT has many advantages such as high remanent polarization intensity, quick reaction speed and high Curie temperature and anti-radiation performance. It is being widely investigated as it can be mainly used in detection, conversion, disposal and memory of information.The B-site composite dielectric ceramics Pb[Zr0.85(Mn1/3Sb2/3)0.05Ti0.10]O3 (abbreviated as PMS-PZT) and Pb(Zr0.925Fe0.025Nb0.025Ti0.025)O3(abbreviated as PFN-PZT) were selected to be researched in this work. Sr2+ and MnO2 were doped in PMS-PZT materials, while CeO2 and Dy3+ were doped in PFN-PZT ceramics. The dopants can manufacture the different kinds of point defects, and then change the order degree of atom in equilibrium position. The effects of substitution on A and B sites on the structure and properties have been studied by the analysis of dielectric properties, body conductance ratio and XRD, SEM, IR, UV-vis spectra. The mechanisms have been also tentatively discussed.The influence of dopants on Ti-O octahedrons aberration and body conductivity was discussed via measuring the optical and ferroelectric properties. The results show that the IR and UV-vis spectra both change corresponding disciplinarily with the change of doping concentration, the radial and electronegativity of irons. The UV-vis absorption band is also affected by the radial and electronegativity of irons.In addition, it is found that the phase structure doesn't change after doping through the analysis of XRD. With some dopants, the tripartite phase and tetragonal phase coexist and the radial of grains change. The changes of grains'radial are consistent with the analysis of SEM.The PZT95/5 ferroelectric materials doped by Sr2+ and CeO2 have low dielectric constant and dielectric loss, while the body conductance ratio of the ceramics doped by Dy3+ decreases, which have important significance in practice. In addition, the factors which impact the dielectric and conductivity properties of ferroelectrics are discussed in this paper, which is the reference of manufacturing the ferroelectric ceramics that have low dielectrical loss, low dielectrical constant and low conductance ratio in future. And the microstructure and optical properties were researched together in this work. Their mechanism has been discussed.