Epitaxial BiFeO3 nanostructures fabricated by differential etching of BiFeO3 films

Abstract
We report on differential etching behavior of the different orientations of the polarization in BiFeO3 (BFO), similar to other ferroelectrics, such as LiNbO3. We show how this effect can be used to fabricateepitaxial BiFeO3nanostructures. By means of piezoresponse force microscopy(PFM) domains of arbitrary shape and size can be poled in an epitaxial BiFeO3film, which are then reproduced in the film morphology by differential etching.Structures with a lateral size smaller than 200 nm were fabricated and very good retention properties as well as a highly increased piezoelectric response were detected by PFM.