Conduction at domain walls in insulating Pb(Zr$_{0.2}$Ti$_{0.8}$)O$_3$ thin films

TL;DR

This study demonstrates electrical conduction at 180° ferroelectric domain walls in Pb(Zr0.2Ti0.8)O3 thin films, revealing nonlinear, thermally activated behavior linked to domain wall structure and defect segregation.

Contribution

It provides the first evidence of conduction at ferroelectric domain walls in PZT thin films, expanding understanding of domain wall functionalities beyond BiFeO3.

Findings

Conduction at 180° domain walls shows nonlinear I-V characteristics.

High-temperature conduction is thermally activated.

Conduction stability is maintained over time.

Abstract

Among the recent discoveries of domain wall functionalities, the observation of electrical conduction at ferroelectric domain walls in the multiferroic insulator BiFeO3 has opened exciting new possibilities. Here, we report evidence of electrical conduction also at 180{\deg} ferroelectric domain walls in the simpler tetragonal ferroelectric PZT thin films. The observed conduction shows nonlinear, asymmetric current-voltage characteristics, thermal activation at high temperatures and high stability. We relate this behavior to the microscopic structure of the domain walls, allowing local defects segregation, and the highly asymmetric nature of the electrodes in our local probe measurements.