Relationship between Phase Formation and Calcination Temperature of Sol-Gel Derived PLT Thin Film

Two kinds of precursors, being transparency and milky in status respectively, were pre- pared. Thin films of Pb0.9La0.15TiO3 were coated on glass substrates with the two precursors added with or without crystallite nano powders of Pb0.5La0.15TiO3 respectively by dip-coating methods. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and dielectric spectroscopy were respectively used to observe the morphology, phase status and dielectric constant of the films. In conclusion, the initial temperature of forming the perovskite phase of Pb0.9La0.15TiO3 thin film derived from the milky precursor is 40- 50℃ lower than that from transparency precursor. On the other hand, crystal lattice of the perovskite phase of the film derived from the transparency precursor decreases while the calcination temperature is in high level of about 550℃ and up. The Curie point is near room temperature when the film is calcined at about 525 . And the solid solubility of La in the perovskite phase decreases with increasing the calculation temperature of the film, and vice versa.