Domain tuning in mixed-phase BiFeO3 thin films using vicinal substrates

TL;DR

This study demonstrates how vicinal substrates can be used to control and reduce domain variants in highly-strained BiFeO3 thin films, enhancing understanding of phase evolution and polarization behavior.

Contribution

It introduces a method to tune ferroelectric domains in BiFeO3 films via substrate surface symmetry breaking, achieving single-domain films on highly-miscut substrates.

Findings

Single-domain BiFeO3 films achieved on large-miscut substrates.

Reduction of structural variants in mixed-phase nanodomains.

Enhanced understanding of phase evolution in strain-driven systems.

Abstract

The structural and ferroelectric domain variants of highly-strained BiFeO3 films grown on vicinal LaSrAlO4 substrates were studied by piezoelectric force microscopy and high-resolution X-ray reciprocal space mapping. Through symmetry breaking of the substrate surface, ferroelastic domain variants in the highly-strained MC phase BiFeO3 can be greatly reduced. Single-domain film can be obtained on substrates with large miscut angle, which is accompanied by the reduction of structural variants in the mixed-phase nanodomains. These findings lead to better understanding of the phase evolution and polarization rotation process in the strain-driven morphotropic phase system.