EFFECT OF CRYSTALLOGRAPHIC ORIENTATION ON FERROELECTRIC PROPERTIES OF PBZR0.2TI0.8O3 THIN-FILMS

We report on the effect of cooling rate on the crystallographic orientation and ferroelectric properties of PbZr0.2Ti0.8O3 (PZT) thin films grown on a lattice matched bottom electrode such as c-axis oriented Y-Ba-Cu-0 (YBCO). The cooling rate from deposition temperature influences the crystallographic orientation of the ferroelectric c axis of the PZT film as well as the electrical properties of the YBCO bottom electrode. As the volume fraction of the ferroelectric phase with the c axis in the plane of the film becomes higher, the hysteresis loops become more rounded and the polarization values become smaller. Highly c-axis oriented films, obtained by cooling from the growth temperature at 20-degrees-C/min, show an almost square hysteresis loop with the largest polarization values.