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arXiv · 2508.08474

When Surface Dynamics Fakes Symmetry -- Oxygen on Rh(100) Revisited

Lutz Hammer·Tilman Kißlinger·Margareta Wagner·Reinhard B. Neder·Michael Schmid·Ulrike Diebold·M. Alexander Schneider
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Abstract

Heating a long-range ordered adsorbate phase beyond its stability temperature does not necessarily result in a disordered phase, it can also break up into heavily fluctuating ordered domains. Temporal and/or spatial averaging over these fluctuations may give the impression of both a wrong periodicity and a false local symmetry. This can happen even below liquid-nitrogen temperature, so that the true nature of the phase might remain undetected. We demonstrate this scenario at the catalytically active Rh(100) surface covered by 1/2 monolayer of oxygen, using quantitative low energy electron diffraction (LEED), variable-temperature scanning tunneling microscopy (STM) and density functional theory (DFT). Using the example of CO adsorption, we show that local symmetry can have a decisive influence on the binding energy and thus the chemical reactivity.

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Lutz Hammer, Tilman Kißlinger, Margareta Wagner, Reinhard B. Neder, Michael Schmid, Ulrike Diebold, M. Alexander Schneider. 2025-08-11. When Surface Dynamics Fakes Symmetry -- Oxygen on Rh(100) Revisited. https://doi.org/10.1103/5wmb-kmjb

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