Partial decoupling between strain and polarization in mono-oriented Pb(Zr0.2Ti0.8)O3 thin film

TL;DR

This study investigates the structural evolution and strain-polarization relationship in mono-oriented Pb(Zr0.2Ti0.8)O3 thin films using temperature-dependent X-ray diffraction, revealing partial decoupling between strain and polarization.

Contribution

It provides detailed measurements of lattice parameters and polarization variation, and compares experimental strain evolution with theoretical phase diagrams.

Findings

Polarization-induced tetragonality differs from elastic tetragonality.

Misfit strain evolution aligns with theoretical temperature-misfit strain phase diagram.

Temperature affects the polarization and strain relationship in the thin film.

Abstract

The structural evolution of epitaxial mono-oriented (i.e. with the c-axis perpendicular to the interface) ferroelectric Pb(Zr0.2,Ti0.8)O3 thin film has been investigated, using high resolution, temperature dependent, X-ray diffraction. The full set of lattice parameters was obtained, it allowed to estimate the variation of the polarization as a function of temperature, underlying the difference between the polarization-induced tetragonality and the elastic one. The temperature evolution of the misfit strain has been calculated and found to be in good agreement with the theoretical temperature-misfit strain phase diagram