文章基本信息

标题：Giant optical enhancement of strain gradient in ferroelectric BiFeO3 thin films and its physical origin
本地全文：下载
作者：Yuelin Li ; Carolina Adamo ; Pice Chen 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2015
卷号：5
期号：1
DOI：10.1038/srep16650
语种：English
出版社：Springer Nature
摘要：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 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.