Low temperature UHV scanning tunneling/atomic force microscope system

The microscope is specially configured to allow for accurate navigation of the scanned tip to nanoscale devices. The system can image the atomic structure of nanoscale devices.  Furthermore, the system will be equipped with in-situ evaporators and sources (shared with the transport measurement system), which allow the proposed investigations on the impact of adsorbates.  The microscope is capable of operating at lower temperature than the system at Maryland, enabling studies of impurities with lower diffusion barriers such as potassium and other weakly adsorbed species. The lower temperature range also provides finer energy resolution for the spectroscopy measurements.

Ultra High Vacuum Transport Measurement Station (4-500K)

Unique transport measurement projects being pursued in our laboratory are enabled by a ultra high vacuum transport measurement station. The station, shown left, is equipped with an 80 liter/sec turbo and a 300 liter / sec ion pump, which ensure fast pump down time and low noise environment for transport measurements.  Typical UHV generation time is 10 hours from the initial pump down.  The base pressure is 2*10^-10 torr.    

Temperature range of the liquid helium cryostat, LT-3B from Advanced Research System, is 4-500 K with typical cooling time of 40 minutes from the maximum to minimum temperature. The sample in the cryostat faces down towards a source flange, which can be equipped with atomic hydrogen source, ion beam gun, electron beam evaporator, thermal evaporator, alkali metal getters or variable leak valve all available at UCF. Residual gas analyzer, RGA 300 from Stanford Research Systems, is in direct line of sight to the source flange and 17° off axis from the cryostat to enable monitoring the flux at the sample.