Tuning of the depolarization field and nanodomain structure in ferroelectric thin films

TL;DR

This paper investigates how inserting ultrathin dielectric spacers at metal-ferroelectric interfaces can tune depolarization fields, thereby controlling nanoscale domain formation and polarization stability in ferroelectric thin films.

Contribution

It introduces a method to modulate depolarization fields via interface engineering to control ferroelectric domain structures.

Findings

Depolarization field strength can be tuned by dielectric spacer insertion.

Nanoscale domain configurations are controllable through interface modifications.

Polarization stability is affected by the engineered depolarization fields.

Abstract

The screening efficiency of a metal-ferroelectric interface plays a critical role in determining the polarization stability and hence the functional properties of ferroelectric thin films. Imperfect screening leads to strong depolarization fields that reduce the spontaneous polarization or drive the formation of ferroelectric domains. We demonstrate that by modifying the screening at the metal-ferroelectric interface through insertion of ultrathin dielectric spacers, the strength of the depolarization field can be tuned and thus used to control the formation of nanoscale domains. Using piezoresponse force microscopy, we follow the evolution of the domain configurations as well as polarization stability as a function of depolarization field strength.