Probing Local Ionic Dynamics in Functional Oxides at the Nanoscale
A scanning probe microscopy technique for probing local ionic dynamics in electrochemically active materials based on the first-order reversal curve current–voltage (FORC-IV) method is presented. FORC-IV imaging mode is applied to a Ca-substituted bismuth ferrite (Ca-BFO) system to separate the electronic and ionic phenomena in this material and visualize the spatial variability of these behaviors. The variable-temperature measurements further demonstrate the interplay between the thermally and electric-field-driven resistance changes in Ca-BFO. The FORC-IV is shown to be a simple, powerful, and flexible method for studying electrochemical activity of materials at the nanoscale and, in conjunction with the electrochemical strain microscopy, it can be used for differentiating ferroelectric and ionic behaviors.
Related Article: Yuanyuan Zhang, Xuan Zhang, Jiafei Lyu, Ken-ichi Otake, Xingjie Wang, Louis R. Redfern, Christos D. Malliakas, Zhanyong Li, Timur Islamoglu, Bo Wang, Omar K. Farha|2018|J.Am.Chem.Soc.|140||doi:10.1021/jacs.8b06789