Transformation dependence of lead zirconate titanate (PZT) as shown by PiezoAFM surface mapping of Sol-gel produced PZT on various substrates.

摘要

PZT was grown on STP (Si/SiO2/Ti/Pt (Ti 5nm, Pt 100nm)), SAP (Si/Si3N4/Al/Ti/Pt(Al 100nm, Ti 10nm, Pt 15nm)) and GI (Glass/ITO(Indium Tin Oxide)). In eachcase the PZT underwent the same heat treatment, 200ºC for 2 minutes and then530ºC for 5 minutes. The extent of perovskite formation was evaluated usingPiezoresponse force microscopy (PFM). This provided information about thedomain orientation and spatial distribution of ferroelectric material in the PZT film.This showed that PZT/STP underwent complete transformation to the perovskitephase. However, for the PZT/SAP and GI incomplete transformation to theperovskite occurred. A system of rosettes surrounded by an amorphous matrixdeveloped. The size and density of the PZT rosettes on the surface was found tobe substrate dependent. For Gi/PZT the density of rosettes formation is ca. 1/μm2,compared to 4/μm2 for PZT/SAP. The rosettes for the PZT on GI grow a maximumsize of 2μm, which compares to 1μm for PZT on SAP. Differences in the observedgrowth rate and nucleation density are associated with the back electrode stabilityand crystal structure, effects that will be discussed in this paper.