PREPARATION AND PROPERTIES OF SOL-GEL DERIVED LA-DOPED PBTIO3 THIN-FILMS

Lanthanum-doped lead titanate thin films with perovskite phase were fa bricated by sol-gel spin-on process. Effect of lanthanum doping on the crystal structure, film orientation, microstructure, and ferroelectri c/dielectric properties of the films were studied. The films showed va rious degrees of (100) orientation, depending mainly on the substrate used and the La content. The addition of La caused chang es in the fil m microstructure. Rosettes distributed in a matrix were observed for t he (Pb0.7La0.2)TiO3 films. The dielectric constant of the films genera lly increased with the increasing La content and the heating temperatu re. (Pb0.7La0.2)TiO3 film heated at 800 degrees C has a dielectric con stant of about 650.