SKM 2023 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 97: Focus Session: Scanning Probe Microscopy with Quartz Sensors IV
O 97.7: Talk
Friday, March 31, 2023, 12:15–12:30, TRE Ma
Benchmarking atomically defined probe tips for NC-AFM experiments — Damla Yesilpinar1, Bertram Schulze Lammers1, Alexander Timmer1, Zhixin Hu2, Wei Ji3, Saeed Amirjalayer1, Harald Fuchs1, and •Harry Mönig1 — 1Westfälische Wilhelms-Universität, Münster, Germany — 2Tianjin University, Tianjin, China — 3Renmin University of China, Beijing, China
Controlling the identity of the tip-terminating atom or molecule in NC-AFM constitutes a milestone in surface science. We consolidate the interpretation of such studies by directly comparing the performance of four atomically defined tips: Cu-, Xe-, CO-, and O-terminated copper (CuOx-) tips. Besides their imaging performances on a metal oxide, we directly compared their capabilities in force mapping during the lateral manipulation of single adsorbed atoms. Expectedly, Cu-tips strongly react with the surface inhibiting stable imaging and picking up the atoms to be manipulated. The chemically inert Xe- and CO-tips, allow entering the repulsive force regime. However, their flexibility leads to dynamic tip bending and pronounced artefacts due to the strongly varying potential above the oxide. Furthermore, tip deflection prevents reaching sufficient threshold forces along manipulation trajectories with high energy barriers. In contrast, the combination of moderate chemical passivation and high stiffness of CuOx-tips turned out decisive for a distinct chemical-specific contrast. Moreover, this results also in a superior performance in the manipulation experiments where their high mechanical stability allows quantitative force measurements also along the trajectories with high energy barriers.