Nanosecond Optically Induced Phase Transformation in Compressively Strained BiFeO3 on LaAlO3

TL;DR

This study demonstrates that above-bandgap optical illumination can rapidly induce phase transformations in compressively strained BiFeO3, enabling nanosecond-scale control of ferroelectric phases through boundary motion.

Contribution

It reveals a new optical method to control phase transformations in BiFeO3, advancing ultrafast manipulation of ferroelectric and multiferroic materials.

Findings

Optical excitation causes a phase change to an untilted T-like phase.

Out-of-plane lattice expansion occurs in the T-like phase.

Phase transformation proceeds via boundary motion at phase interfaces.

Abstract

Above-bandgap optical illumination induces a transformation from tilted tetragonal-like (T-like) and rhombohedral-like (R-like) phases to an untilted T-like phase in compressively strained BiFeO3. Optical excitation leads to an out-of-plane lattice expansion in the T-like phase. The transformation proceeds in regions with boundaries between the T-like and tilted R-like and tilted T-like phases, consistent with the motion of a boundary. The optically induced transformation indicates that there are new optically driven routes towards nanosecond-scale control of phase transformations in ferroelectrics and multiferroics.