Properties And Properties Of PZT-based Ferroelectric Materials

Lead zirconate titanate (PZT) material has has shown good ferroelectric, dielectric piezoelectric and pyroelectric properties. It was widely studied. In previous work, we investigated the dielectric constant, dissipation factors and the ferroelectric properties of PZT ferroelectric ceramics prepared by the sol-gel method. In this study, the mainly work is to study the ferroelectric properties of PZT ceramics futher more. The model function and the equivalent circuit was used to analysis the dielectric relaxation phenomena of the PZT ceramic.The PZT film has been widely used in micro-capacitor dynamic random access memory (DRAM), non-volatile ferroelectric random access memory (FRAM), and photoelectric open lightfields. The properties of the binary system of PZT piezoelectric film doped with REE-for example Er, Gd, Eu, Nd, Y, La and so on-has been improved in some certain aspects. Praseodymium and lanthanum are rare earth element of the same cycle, however, the praseodymium doped in the PZT film are rarely reported. Therefore, this study will focus on PZT thin film dropped with praseodymium.The main work we did and the work we got of PZT ceramic are as follows:(1) The PZT ceramics was prepared by the method of sol-gel and Segment sintering.(2) The Cole-Cole diagram of the PZT ceramics in different temperatures was drawn. And the relaxation time of the PZT ceramic samples was obtained with the use of the model function.(3) With the use of the equivalent circuit to simulate the piezoelectric ceramic vibrator we can get a conclusion that in the85MHz-120MHz the response of the sample can be represented with a RLC series resonant circuit. The resonant frequency of the sample is97.12MHz, and the loss is very low. Compared with the general piezoelectric vibrator PZT95/05nano-ceramic is a low frequency capacitor with the capacitance tend to0F. For Pr-doped PZT thin film the work and the results are as follows:(1) The PZT film droped with Pr was prepared by the method of sol-gel.(2) After the test of XRD, we can know that at the temperature of750degrees, there are no impurities in samples, and they will show (110) preferred orientation.(3) With the increase of zirconium, the relative dielectric constant of the film first increased, the relative dielectric constant of the film will changed. It will be increased at first and then decreased at the test frequency of1KHz. The relative dielectric constant reaches its maximum when Zr/Ti=0.17.(4) On the other hand, when the content of praseodymium is different also makes a great difference in the nature of the film. When the content of the praseodymium increase (2%-5%), the dielectric constant will be increased at first and then decreased.When the content of praseodymium was3%, the dielectric constant was the highest.