Research Facilities
Low-temperature ultra-high vacuum scanning tunneling microscope (Omicron GmbH)
The setup consists of two chambers, the actual STM chamber and a sample preparation chamber,
that are independently pumped by means of an ion pump and additional titanium sublimation pump,
ensuring operation at a base pressure below 5.10-11 mbar in both chambers. The preparation chamber
is equipped with a heater stage (Tmax ≈ 1200 K), an argon ion gun (AG21 from VG Scientific) and two
evaporation cells (EFM3 from Omicron GmbH). The microscope is mounted in a thermally shielded compartment
directly attached to a cryostat, allowing measurements at room temperature (Tsample ≈ 300 K) and at low temperatures
(Tsample ≈ 78 K or 4.5 K). A spring suspension system with Eddy current damping ensures optimal vibration isolation,
ensuring a z-resolution better than 0.1 nm.
Ultra high vacuum transportable vessel (home-built)
To avoid sample contamination and oxidation, a home-built UHV transport vessel was developed and made compatible with the MBE apparatus, the cluster deposition apparatus and the LT UHV STM setup. The vessel consists of a small chamber provided with a long transport arm and an ion pump that can run autonomously for 24 hours using a battery (base pressure typically in the 10-10 mbar range).
