Dry Low-Temperature STM System (1K)
The pulse tube STM system, which is still under construction, does not require a cryostat. It is brought to a temperature of 1.2K using a two-stage pulse tube cooler and a Joule-Thomson stage. A special passive damping system with negative stiffness was developed to reduce the mechanical vibration of the cooling head on the STM. A new ceramic scanning tunneling microscope was designed and built for this application using mechanical simulations.
At present, the UHV facility consists of two chambers and an load-lock with an MBE evaporator. On the left is a small preparation chamber with a sputter gun and a high temperature sample heater (up to 2300K). In the center the STM chamber is located. On the right is space for another MBE chamber, but this will be built in the future.