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

ABSTRACT: Through mapping of the spatiotemporal strain profile in ferroelectric BiFeO3 epitaxial thin films, we report an optically initiated dynamic enhancement of the strain gradient of 10(5)-10(6)?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.

SUBMITTER: Li Y

PROVIDER: S-EPMC4653733 | biostudies-literature | 2015 Nov

REPOSITORIES: biostudies-literature

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

Li Yuelin Y Adamo Carolina C Chen Pice P Evans Paul G PG Nakhmanson Serge M SM Parker William W Rowland Clare E CE Schaller Richard D RD Schlom Darrell G DG Walko Donald A DA Wen Haidan H Zhang Qingteng Q

Scientific reports 20151120

Through mapping of the spatiotemporal strain profile in ferroelectric BiFeO3 epitaxial thin films, we report an optically initiated dynamic enhancement of the strain gradient of 10(5)-10(6) 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 poss ...[more]

PMID: 26586421

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