Giant optical enhancement of strain gradient in ferroelectric BiFeO3 thin films and its physical origin

Yuelin Li*, Carolina Adamo, Pice Chen, Paul G. Evans, Serge M. Nakhmanson, William Parker, Clare E. Rowland, Richard D. Schaller, Darrell G. Schlom, Donald A. Walko, Haidan Wen, Qingteng Zhang

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

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Abstract

Through mapping of the spatiotemporal strain profile in ferroelectric BiFeO3epitaxial thin films, we report an optically initiated dynamic enhancement of the strain gradient of 105-106 m-1 that lasts up to a few ns depending on the film thickness. Correlating with transient optical absorption measurements, the enhancement of the strain gradient is attributed to a piezoelectric effect driven by a transient screening field mediated by excitons. These findings not only demonstrate a new possible way of controlling the flexoelectric effect, but also reveal the important role of exciton dynamics in photostriction and photovoltaic effects in ferroelectrics.

Original languageEnglish (US)
Article number16650
JournalScientific reports
Volume5
DOIs
StatePublished - Nov 20 2015

ASJC Scopus subject areas

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