Fine tuning epitaxial strain in ferroelectrics: PbxSr(1-x)TiO3 on DyScO3

TL;DR

This paper demonstrates how to precisely control epitaxial strain in ferroelectric PbxSr(1-x)TiO3 films by combining composition and substrate choice, supported by theoretical phase diagrams and experimental validation.

Contribution

It introduces a method to continuously tune epitaxial strain in ferroelectric films using composition and substrate selection, supported by a calculated phase diagram and experimental results.

Findings

Phase boundary between in-plane and out-of-plane ferroelectric phases at x ≈ 0.8

Good agreement between experimental films and theoretical phase diagram

Continuous control of epitaxial strain achieved through composition and substrate choice

Abstract

Epitaxial strain can be used to modify the properties of ferroelectric thin films. From the experimental viewpoint, the challenge is to fine-tune the magnitude of the strain. We illustrate how, by using a suitable combination of composition and substrate, the magnitude of the epitaxial strain can be controlled in a continuous manner. The phase diagram of PbxSr1-xTiO3 films grown epitaxially on (110)-DyScO3 is calculated using a Devonshire-Landau approach. A boundary between in-plane and out-of-plane oriented ferroelectric phases is predicted to take place at $x \approx$ 0.8. A series of PbxSr1-xTiO3 films grown by MBE show good agreement with the proposed phase diagram