Ultra-high vacuum system with combined STM/SFM operating at low temperatures

• Subject Area: Condensed Matter Physics
• Term: Funded in 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 452924260

We describe a Scanning Force Microscope that works in ultra-high vacuum at low temperatures in a He bath cryostate. The instrument is suitable to obtain atomic resolution on various surfaces. In particular the tip is cooled and this allows to place an atom or molecule on the tip and to measure the chemical interaction between this atom or molecule and the surface. We choose a beam-deflection detection method in order to be able to choose freely the spring constant of the cantilever. This allows us to measure both short-range chemical interactions as well as electrostatic interactions. The chemical interactions are decisive to obtain atomic resolution on molecules, to understand new types of chemical reactions and to study particular atomic states of molecules that are important for molecular electronics. The electrostatic forces are important to understand electronic transport and electronic properties of nanostructures that are also to be used for molecular electronics purposes. The idea is to replace the functional units in computer chips, today fabricated from semiconductors, by molecules and to support this technological transition by a deeper understanding of the fundamental properties of molecules and nanostructes on surfaces.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Ultrahochvakuum-System mit kombiniertem Tieftemperatur-STM/SFM
• Instrumentation Group: 5091 Rasterkraft-Mikroskope
• Applicant Institution: Universität Potsdam
• Leader: Professorin Dr. Regina Hoffmann-Vogel