Effect of base electrode on the crystallization and electrical properties of PLT

Lead lanthanum titanate (28% La) films, 900–1500 Å thick, have been deposited by the sol-gel technique on Ir/Si and Pt/Ti/SiO2 substrates. The films have been rapidly thermal annealed for 1–4 min. at 650 °C and have been characterized by X-ray diffractometry, scanning electron microscopy and by electrical measurements. The dielectric constant of the PLT films deposited on the Pt electrodes reached a maximal value of 660, while for those deposited on the Ir electrodes it reached a maximal value of 775. The variation of the values of the dielectric constants of the different samples appears to be controlled mainly by the concentration of Pb in the films.