Figure 2: Structure of the negatively poled surface.

(a) Displacement vectors between the Pb and ZrO/TiO columns overlaid with the ABF image. The yellow arrows represent displacement vectors. The atomic layers are labelled by the numbers. Scale bar, 0.5 nm. (b) Mean of the lattice parameter in [001] direction. Six data points were averaged to calculate the Pb lattice and five data points were averaged to plot ZrO/TiO lattice. The error bar is the s.d. The green colour highlights the surface region with different atomic configuration. (c) The z-component of displacement and polarization. Six data points were averaged to plot Pb displacement and five data points were averaged to plot ZrO/TiO displacement. The error bar is the s.d. (d) Vector map of the displacement between the cation and anion columns. Scale bar, 0.5 nm. (e) The magnitude map of the displacement between the cation and anion columns. The black dashed line highlights distinct magnitude between the left surface zone and right bulk-like region. (f) The long and short bond length of Pb–O along z-direction. Six data points were averaged to plot the Pb–O bond length. The error bar is the s.d. The pink band highlights the shorter Pb–O length, which directly represents the magnitude of polarization in PZT. The grey band highlights the longer Pb–O length. The dashed line 159 pm is calculated from the structure model in ref. 23. The arrow indicates the position of the charged 180° domain wall.