Enhanced Piezoelectric Response in Nano-Patterned Lead Zirconate Titanate Thin Films

Abstract

In this work, Pb(Zr,Ti)O3 thin films were used to fabricate well-ordered nanodot arrays by means of nanosphere lithography. This technique is based on a two-step etch process that enables excellent control of the fabrication of ordered nanodisc arrays of defined height, diameter, and pitch. Piezoresponse force microscopy was used to investigate both non-patterned and patterned films. The topography and both the out-of-plane and the in-plane polarization were deduced in this mode. Grains of nanodots with a low aspect ratio form domain structures comparable to domains in non-patterned two-dimensional films. In contrast, nanodots with a higher aspect ratio form particular structures like bi-sectioned domain assemblies, c-shaped domains or multi-domains surrounding a center domain. The patterning of the ferroelectric material was shown to affect the formation of ferroelectric domains. The initial polycrystalline films with random polarization orientation re-orient upon patterning and then show domain structures dependent on the nanodisc diameter and aspect ratio.

Nano-patterned PZT films for perspective functional materials

“…The reasons for the increase in pyroand piezoelectric coefficients are still under discussion but taking advantage of this effect offers a large variety of perspective applications of ferroelectric materials. Recently, remarkable increases in the local piezoresponse of nanopatterned PZT films were observed, both in the plane as well as out of the plane [6]. This enhancement is caused by the breakup of grains in order to compensate the stress induced by the polarization field and depends on the lateral dimensions and aspect ratio of the structures.…”