Dresden 2026 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 36: Focus Session: Mineral-water interfaces II

O 36.3: Vortrag

Dienstag, 10. März 2026, 11:15–11:30, HSZ/0403

Surface Structure of Polar Silver Iodide (0001) in Various Liquids: No Indication for a Surface Reconstruction — •Kim Noelle Dreier, Annamaria Latus, Ralf Bechstein, and Angelika Kühnle — Physical Chemistry I, Department of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany

Silver iodide (AgI) has long been known as a material that induces precipitation in clouds. The superior ice nucleation ability is commonly explained by the close lattice match between β-AgI(0001) and the basal plane of ice. However, this surface is polar, indicating that a stabilization mechanism should be present. Here, we investigate the Ag-terminated β-AgI(0001) and the I-terminated β-AgI(000-1) surfaces in water and compare the results with images recorded in n-dodecane, 0.1 M NaCl and 0.1 M KI aqueous solutions. Strikingly, high-resolution images consistently reveal a bulk-truncated structure. These findings align with observations at a larger scale, which neither indicate any surface reconstruction. Although the observed structures reveal a variety of features and depend on the surface termination, some general conclusions can be drawn. Firstly, in solvents with poor AgI solubility, only minor changes are observed. Secondly, the images taken in KI solution exhibit patterns that are characteristic of mineral dissolution and growth. Thus, even in a situation where AgI can and does dissolve, no indication for a surface reconstruction can be found. These results shed new light onto the surface structure of β-AgI(0001), challenging the expectation that a surface reconstruction is present under ambient conditions.

Keywords: ice nucleation; silver iodide; polar surface; surface reconstruction; atomic force microscopy