Fig. 4: Enhanced resolution topography, PFM and cAFM images of PZT surface with 180°-DWs.

In the two examples (upper and lower row) a square in a square poling done by a AFM-tip produces different domain patterns. a–c A peculiar a-domain formation behavior is observed. After poling, a large number of short a-domains form at the position of the 180°-DW and partially overlap with it. This is readily seen in the topography a and PFM-amplitude b image. From the cAFM image of the same area c, a zigzack like conductive trace is recognizable, but it can not be determined if the conduction stems from the 180°-DW or the new short 90°-DWs. d–f A zoomed view on closely spaced 180°-DWs and 90°-DWs. In this set of images, it is clear that the 180°-DW exists as a stand-alone object without any associated zigzag-shaped a-domains. The parts marked in red are particularly interesting, here the 180°-DW is readily seen in the PFM image e (no topography changes in d) with a curved shape and without any ferroelastic a-domains in its close proximity. This stand-alone 180°-DW section produces a conduction response clearly seen in the cAFM image f.