Nanostructured heterophase thin films of lead zirconate titanate

The results of a comprehensive study of electrophysical and photoelectric properties of capacitor structures are analyzed within the proposed model of Pb(ZrTi)O-3 (PZT) films with an excess lead content, which is based on the presence of heterophase intergrain boundaries. It is shown that aging of thin-film capacitor structures is accompanied by a significant increase in the oxygen content in submicron PZT films, as well as by the modification of elemental and phase compositions of the interfaces. It is confirmed experimentally that a decrease in the switching charge in the aged PZT films is due to the oxygen sorption at heterophase crystallite boundaries containing lead oxide and to pinning of the polarization in regions adjacent to the charged boundaries. It is demonstrated that the current-voltage characteristics of the capacitor structures are described in terms of the mechanisms of space-charge-limited currents.