SOL-GEL PZT THIN-FILMS ON NICKEL-ALLOY ELECTRODES

The Ni alloy electrode was used for a bottom electrode of PZT thin fil ms prepared by sol-gel process. Although PZT films were crystallized o n soda-lime glass substrates with the alloy electrodes at a relatively low temperature of 500 degrees C, second phases of Pb3O4 and ZrTiO4 w ere produced on the electrode in addition to the perovskite PZT phase. In order to prevent the second phases forming, the heat treatment tim e of the electrode was increased to obtain the thicker Al2O3 layer on the alloy electrode. The second phases decreased with increasing the h eat treatment time; however, the phases did not disappear. When BaTiO3 films were inserted between the electrodes and PZT films, the PZT sin gle phase was obtained. The tan delta of the films decreased with decr easing the amount of the second phases, finally it became 3.9%, the fi lm of which possessed a remanent polarization of 20 mu C/cm(2).