Nanoscale Patterns on Polar Oxide Surfaces Mikołaj Lewandowski Irene M. N. Groot Zhi-Hui Qin Tomasz Ossowski Tomasz Pabisiak Adam Kiejna Anastassia Pavlovska Shamil Shaikhutdinov Hans-Joachim Freund Ernst Bauer 10.1021/acs.chemmater.6b03040.s001 https://acs.figshare.com/articles/journal_contribution/Nanoscale_Patterns_on_Polar_Oxide_Surfaces/4029327 Polar ionic surfaces with bulk termination are inherently unstable because of their diverging electrostatic surface energy. Nevertheless, they are frequently observed in nature, mainly because of charge neutralization by adsorbates, but occur also under atomically clean conditions. Several mechanisms have been invoked to explain the stability of atomically clean polar surfaces, but the frequently observed periodic nanoscale pattern formation has not yet been explained. Here we propose that long-range interactions between alternating electropositive and electronegative regions of different surface terminations minimize the electrostatic energy of the surface and thus stabilize the nanoscale pattern. This is illustrated using the example of polar Fe oxide surfaces by combining scanning tunneling microscopy and spectroscopy results with results from density functional theory-based calculations and dipole–dipole interaction models. 2016-09-28 00:00:00 electronegative regions Polar Oxide Surfaces Polar charge neutralization bulk termination surface energy nanoscale pattern formation Fe oxide surfaces theory-based calculations nanoscale pattern Several mechanisms surface terminations scanning tunneling microscopy spectroscopy results Nanoscale Patterns