Berlin 2008 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 55: Poster Session III - MA 141/144 (Methods: Atomic and Electronic Structure; Particles and Clusters; Heterogeneous Catalysis; Semiconductor Substrates: Epitaxy and Growth+Adsorption+Clean Surfaces+Solid-Liquid Interfaces; Oxides and Insulators: Solid-Liquid Interfaces+Epitaxy and Growth; Phase Transitions; Metal Substrates: Adsorption of Inorganic Molecules+Epitaxy and Growth; Surface Chemical Reactions; Bimetallic Nanosystems: Tuning Physical and Chemical Properties; Oxides and insulators: Adsorption; Organic, polymeric, biomolecular films; etc.)

O 55.43: Poster

Mittwoch, 27. Februar 2008, 18:30–19:30, Poster F

Design and construction of a 300 mKelvin / 17 Tesla ultra-high vacuum scanning tunneling microscope for molecular studies — •Jörg Schwöbel, Matthias Nohme, Robert Ravlić, Jan Wienhausen, Germar Hoffmann, and Roland Wiesendanger — Institut für Angewandte Physik, Universität Hamburg, Germany

The detailed investigation of molecular excitations and molecular magnetism is a prerequisite to establish molecules as building blocks for tailor made materials. Here, we present the design of a new ultra-high vacuum system for the local study of molecular magnetism with scanning tunneling microscopy (STM) and spectroscopy (STS).

To resolve magnetic molecular levels this system operates at ultra-low temperatures (300 mK), thereby increasing energy resolution, and is equipped with a 17 Tesla magnetic field to achieve splitting of magnetic states. Organic magnetic molecules will be prepared on metal substrates as well as on substrates covered by insulating layers for electronic decoupling. For the preparation of heterogeneous layers from different materials and of single molecules we developed new vacuum components for a flexible growth at temperatures between 1 and 500 K. Metal and molecule evaporators are mounted on individual sample holders. Therefore, evaporators can be easily exchanged and operated in the preparation chamber as well as within the 300 mK cryostat.

We will discuss the design concept of the STM system and the vacuum components we developed on portable evaporators, as well as for the preparation of crystals with high melting temperatures. First results on the in-situ preparation of molecular systems will be presented.