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O: Fachverband Oberflächenphysik

O 68: Poster: Scanning Probe Techniques: Method Development

O 68.10: Poster

Mittwoch, 20. März 2024, 18:00–20:00, Poster C

Non-contact AFM experiments with a diamond tip equipped needle sensor: From field emission to tunneling — •Stefan Schulte^1,2, Sven Just^1,3, Victor I. Kleshch⁴, F. Stefan Tautz^1,3, and Ruslan Temirov^1,2 — ¹Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, Germany — ²II. Physikalisches Institut, Universität zu Köln, Cologne, Germany — ³Fundamentals of Future Information Technology, Jülich Aachen Research Alliance (JARA), Jülich, Germany — ⁴Moscow, Russia

A length extension quartz resonator (needle sensor) equipped with a CVD-grown single crystal diamond needle on the tip is characterized in a room-temperature AFM setup at UHV conditions. The particular setup allows for simultaneous AFM, field emission and tunneling experiments. The diamond tip needle sensor could be a platform to enable the measurements of electrostatic surface potential in scanning quantum dot microscopy (Wagner et al., Phys. Rev. Lett., 2015). We focus on the transition from a non-conductive state of the diamond to a surface-conductive state, which occurs when the surface of the diamond needle is transformed into amorphous carbon at elevated field emission currents. The current-voltages characteristics of the diamond needle are recorded at different distances ranging from the attractive AFM regime to several nm above the surface. Simultaneously recorded AFM signals of the resonant behavior of the sensor reveal the specific transformation processes. Finally, the conductive diamond tip enables tunneling experiments at comparably low bias voltages.

Keywords: non-contact atomic force microscopy; diamond needle; scanning quantum dot microscopy; field emission