The new SIGMA INFINITY UHV SPM is a low-temperature SPM for high-resolution STM, qPlus®-AFM, and spectroscopy experiments. A pulse tube cooler is employed to cool the UHV SPM in a new, unique design. This renewable cryostat, which has no moving parts in the cold head and very long service intervals, belongs to the next generation of cryostats that are independent of cryogenic liquids. The handling of liquid helium or liquid nitrogen is no longer necessary, thus making instrument use simpler and safer. The instrument can stay cold for several months without the need for any maintenance of the cryostat.
For optimum mechanical decoupling, the sensitive SPM is mounted in a dedicated UHV chamber with ports for sample transfer, optical access, and evaporators, and the noisy pulse tube cooler is located in a separate high vacuum chamber. In addition, the SPM head is mechanically decoupled by a spring suspension with eddy current damping.
This unique two-chamber design with incorporated mechanical decoupling units, sophisticated thermal connections, and dedicated acoustic noise cancellation is the key to pm-stability in a temperature range from 10K to 300K.