EFFECT OF EXCESS Pb IN PT LAYERS ON MICROSTRUCTURE AND DIELECTRIC CHARACTERISTIC OF PT/PZT/PT THIN FILMS

ABSTRACT

The Pb_{1 + x}TiO₃/PbZr_0.3Ti_0.7O₃/Pb_{1 + x}TiO₃(PT/PZT/PT) sandwich structure thin films with different excess Pb content (x = 0, 0.05, 0.10, 0.15, 0.20) in PT precursor were prepared by sol-gel method. The XRD results show that the crystalline behave of PT/PZT/PT films is quite different to the PZT films, it is greatly affected by temperature and excess Pb content (x) in PT layers. The excess Pb content (x) in PT layers effects the crystallization of the formation of perovskite-phase of PZT layers through the effect of perovskite-phase formation of the PT layers. The SEM results showed that the dense and uniform of grain size surface morphology of PT/PZT/PT thin films annealed at 650°C appeared when the excess Pb cintent x = 0.05, 0.10 and 0.15. The results of ferroelectric, dielectric constant and dielectric loss characteristic of the films correlated obviously to the crystalline behaviors and excess Pb content(x) in PT layers. A higher remnant polarization and better dielectric constant and dielectric loss characteristic were obtained for the films of excess Pb content x = 0.10 and 0.15 in PT layers.

Keywords:

• Ferroelectric and dielectric characteristic
• excess Pb content
• PT/PZT/PT thin films
• sol-gel

ACKNOWLEDGMENTS

This work is supported by the National Nature Science Foundation of China (No. 60171012) and the key program of National Nature Science Foundation of China (No. 90407023). Especially, the authors deeply appreciate Shiming Wang and Yebing Xu for their assistance in the experiments.