It might seem odd that table salt (NaCl) is such a nice tool for nanotechnology, but it is! It's ideal as a thin insulating layer: it's easy to evaporate, usually forms nice thin islands on metal surfaces, and does a good job separating adsorbates on top from the underlying metal underneath. Salt has been investigated on a number of different surfaces before and when we put it in platinum (Pt(111)), we didn't expect anything exciting. In fact, the STM images appeared similar to those previously published. But our AFM images revealed a tetris-block-like pattern. Working together with theorist Mats Persson, we determined that this pattern is a result of the electrostatic force above the Cl ions - instead of lying at one height above the Pt, they either lie higher or lower above the plane of the Na ions.
For more information, see our publication at Weymouth, Persson and Giessibl Phys Rev B, 105, 035412 (2022)
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