Ferroelectricity in ultra-thin perovskite films

TL;DR

This study demonstrates stable ferroelectric states in ultra-thin perovskite films less than 10 Å thick, highlighting the impact of realistic electrodes and interfaces on polarization stability.

Contribution

It provides new insights into ferroelectricity in ultra-thin films considering realistic electrode effects and metal/oxide interface influences.

Findings

Stable ferroelectric states in films <10 Å thick

Electrode screening affected by work function differences

Ferroelectric PbTiO₃ and BaTiO₃ films exhibit polarization stability

Abstract

We report studies of ferroelectricity in ultra-thin perovskite films with realistic electrodes. The results reveal stable ferroelectric states in thin films less than 10 \AA thick with polarization normal to the surface. Under short-circuit boundary conditions, the screening effect of realistic electrodes and the influence of real metal/oxide interfaces on thin film polarization are investigated. Our studies indicate that metallic screening from the electrodes is affected by the difference in work functions at oxide surfaces. We demonstrate this effect in ferroelectric PbTiO$_3$ and BaTiO$_3$ films.