Atomically Resolved Probe-type Scanning Tunneling Microscope for Use in Harsh Vibrational Cryogen-free Superconducting Magnet
POSTER
Abstract
We present a probe-type scanning tunneling microscope (STM) with atomic resolution that is designed to be directly inserted and work in a harsh vibrational cryogen-free superconducting magnet system. When a commercial variable temperature insert (VTI) is installed in the magnet and the STM is in turn housed in the VTI, a lowest temperature of 1.6 K can be achieved, where the STM still operates well. We have tested it in an 8 T superconducting magnet cooled with the pulse-tube cryocooler (PTC) and obtained atomically revolved graphite and NiSe2images as well as the scanning tunneling spectrum (STS, i.e. dI/dV spectrum) data of the latter near its critical temperature, which show the formation process of the superconducting gap as a function of temperature. The drifting rates of the STM at 1.6 K in X-Y plane and Z direction are 1.15 and 1.71 pm/min respectively.This is important as a cryogen-free magnet system has long been considered too harsh for any atomic resolution measurement.
*This work was supported by the National Key R&D Program of China (Nos. 2017YFA0402903 and2016YFA0401003), National Natural Science Foundation of China (Nos. 21505139, 51627901, 11504339and 11374278), and Chinese Academy of Sciences Scientific Research Equipment (No. YZ201628s).
Presenters
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Wenjie Meng
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High magnetic filed laboratary of the Chinese Academy of Sciences
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory and Hefei Science Center, Chinese Academy of Sciences