Three-dimensional ferroelectric domain imaging of epitaxial BiFeO3 thin films using angle-resolved piezoresponse force microscopy

Abstract

Here we introduce angle-resolved piezoresponse force microscopy (AR-PFM), whereby the sample is rotated by 30 degrees increments around the surface normal vector and the in-plane PFM phase signals are collected at each angle. We obtained the AR-PFM images of BaTiO3 single crystal and cube-on-cube epitaxial (001) BiFeO3 (BFO) thin film on SrRuO3/SrTiO3 substrate, and confirmed that the AR-PFM provides more unambiguous information on the in-plane polarization directions than the conventional PFM method. Moreover, we found eight additional in-plane polarization variants in epitaxial BFO thin films, which are formed to mitigate highly unstable charged domain boundaries. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3487933]