SPACE-CHARGE EFFECTS ON THE FERROELECTRIC (PB,LA)TIO3 THIN-FILM

10 mole% of La-modified lead titanate (PLT) thin films were fabricated on Pt/Ti/SiO2/Si substrates by the sol-gel method. The metal-ferroele ctric-metal (MFM) structures were prepared to observe the electrical p roperties of the thin films. The shift of capacitance vs. voltage (C-V ) curves, and D-E hysteresis loops to the direction of the negative vo ltage indicates that the internal field was existing in the film. The Curie temperature of PLT thin films was 277 degrees C and the remanent polarization and coercive field were 11.4 mu C/cm(2) and 112 kV/cm, r espectively. In order to investigate the effects of space charges in P LT thin films, we have measured discharging current. The discharging c urrent of fatigued sample is much higher than that of initial sample a nd this is because of space charges between the thin film and the elec trode.