Hematite α‐Fe2O3(0001) in Top and Side View: Resolving Long‐Standing Controversies about Its Surface Structure

• DOI: 10.1002/admi.202300602
• Publication Date: 2023-08-21T18:15:14Z
• Authors: Jesús Redondo; Jan Michalička; Florian Kraushofer; Giada Franceschi; Břetislav Šmid; Nishant Kumar; Ondřej Man; Matthias Blatnik; Dominik Wrana; Benjamin Mallada; Martin Švec; Gareth S. Parkinson; Martin Setvin; Michele Riva; Ulrike Diebold; Jan Čechal
• Keywords: Nanomaterials; Energy-dispersive X-ray spectroscopy; Oxidizing agent; Photoemission electron microscopy

Abstract Hematite is a common iron oxide found in nature, and the α ‐Fe 2 O 3 (0001) plane prevalent on nanomaterial utilized photo‐ electrocatalytic applications. The atomic‐scale structure of surface remains controversial despite decades study, partly because it depends sample history as well preparation conditions. Here, comprehensive study performed using an arsenal techniques (non‐contact atomic force microscopy, scanning tunneling low‐energy electron diffraction, X‐ray photoemission spectroscopy) complemented by analyses near region high‐resolution transmission microscopy energy loss spectroscopy. results show that so‐called “bi‐phase” termination forms even under highly oxidizing conditions; (1 × 1) only observed presence impurities. Furthermore, shown biphase actually continuous layer distorted due to mismatch with subsurface layers, thus not proposed mixture FeO(111) phases. Overall, how combining cross‐sectional imaging provides full view can be essential for understanding role near‐surface properties.