Study On The Ferroelectric And Pyroelectric Properties Of Pb(Zr_0.94Ti_0.06)O₃ Thin Film

Ferroelectric films appeared several decades ago and the technology of ferroelectric film appeared in the seventies of twenty century. With the development of film forming technology, this new kind of function material is extensively applied in many fields such as electric technology, laser technology, infrared detection technology and other aspects of engineering technology. Pb(Zr,Ti)O₃(usually abbreviated as PZT) , one of ferroelectric films, appeared in the beginning of the fiftieth. Because varying the ratio of Zr/Ti or adding impurities can improve its properties, PZT was focused by the scientists all over the world.Based on the previous experimental theories, we first study the properties of the PZT thin film the ratio Zr/Ti of which is 94/6 in this thesis. In our experiment, the structure of the PZT thin film sample is Pt/PZT/YBCO/LAO. LAO is the substrate. Pt and YBCO are the top electrode and the bottom electrode separately. YBCO thin film is deposited on the substrate by pulsed laser deposition(PLD). And PZT thin film is epitaxially deposited on the bottom electrode also by PLD. Subsequently, we measure the crystallization by XRD. X-ray diffraction show that under opium conditions, PZT thin film can have good crystallization and obvious orientation. Ferroelectric properties are measured by RT66. The hysteresis loops show that the film has good ferroelectric properties. The curves of frequency Vs dielectric constant and dielectric loss are showed by HP4192. When the frequency is 20KHz, the dielectric constant and dielectric loss are 120 and 0.05 respectively. Relatively low dielectric constant and dielectric loss certifies that PZT is one of the good pyroelectric materials. The pyroelectric coefficient is determined to be 3nC/cm2-K by measuring the photocurrent. In this experiments, the influences of substrate temperature, annealing temperature and added mixture on the properties of PZT thin film are studied.