Crystallization behavior of sol-gel derived Pb(Zr,Ti)O3 thin films and the polarization switching effect on film microstructure

The microstructure of sol-gel derived Pb(Zr,Ti)O3 thin films was investigated using Auger electron spectroscopy (AES) and transmission electron microscopy (TEM). The AES depth profile revealed that the Ti content decreases and the Zr content increases from the bottom through the thickness as a result of the crystallization into perovskite phase. A cross-sectional TEM micrograph showed that the PZT grains are columnar and grow epitaxially from the bottom to the surface. It was also shown that the 2.5-nm-thick interface layer appeared at the top Au electrode-PZT interface after 108 polarization switching cycles, while there was no change at the bottom Pt-PZT interface.