title: Probing local ionic dynamics in functional oxides at the nanoscale.
abstract: 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.
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States. strelcove@ornl.gov
authors.forename: Evgheni
authors.initials: E
authors.lastname: Strelcov
authors.forename: Yunseok
authors.initials: Y
authors.lastname: Kim
authors.forename: Stephen
authors.initials: S
authors.lastname: Jesse
authors.forename: Ye
authors.initials: Y
authors.lastname: Cao
authors.forename: Ilia N
authors.initials: IN
authors.lastname: Ivanov
authors.forename: Ivan I
authors.initials: II
authors.lastname: Kravchenko
authors.forename: Chih-Hung
authors.initials: CH
authors.lastname: Wang
authors.forename: Yung-Chun
authors.initials: YC
authors.lastname: Teng
authors.forename: Long-Qing
authors.initials: LQ
authors.lastname: Chen
authors.forename: Ying Hao
authors.initials: YH
authors.lastname: Chu
authors.forename: Sergei V
authors.initials: SV
authors.lastname: Kalinin