铁电BiFeO₃薄膜中应变梯度的巨大光学增强及其物理起源。
Giant optical enhancement of strain gradient in ferroelectric BiFeO3 thin films and its physical origin.
作者信息
Li Yuelin, Adamo Carolina, Chen Pice, Evans Paul G, Nakhmanson Serge M, Parker William, Rowland Clare E, Schaller Richard D, Schlom Darrell G, Walko Donald A, Wen Haidan, Zhang Qingteng
机构信息
Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Department of Applied Physics, Stanford University, Stanford, CA 94305, USA.
出版信息
Sci Rep. 2015 Nov 20;5:16650. doi: 10.1038/srep16650.
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.
通过对铁电BiFeO₃外延薄膜中的时空应变分布进行映射，我们报告了一种光学引发的应变梯度动态增强，其增强幅度为10⁵ - 10⁶ m⁻¹，持续时间长达几纳秒，具体取决于薄膜厚度。与瞬态光吸收测量结果相关联，应变梯度的增强归因于由激子介导的瞬态屏蔽场驱动的压电效应。这些发现不仅展示了一种控制挠曲电效应的新的可能方式，还揭示了激子动力学在铁电体的光致伸缩和光伏效应中的重要作用。
Zotero 插件