A cryogen-free superconducting magnet based scanning tunneling microscope for liquid phase measurement

Area of Science:

• Condensed Matter Physics
• Biophysics
• Materials Science

Background:

• Conventional scanning tunneling microscopes (STMs) are typically limited to ultra-high vacuum and low temperatures.
• Imaging chemical and biological molecules in solution under high magnetic fields presents significant technical challenges.

Purpose of the Study:

• To develop and demonstrate a liquid-phase STM functional within a high magnetic field (10 Tesla).
• To assess the STM's capability for imaging diverse molecules, including biomolecules, in solution under magnetic fields.

Main Methods:

• Construction of a compact and rigid STM head using dual piezoelectric tubes for variable imaging areas.
• Integration of the STM into a cryogen-free superconducting magnet system.
• Imaging of graphite surfaces and biomolecules (antibodies, plasmid DNA) in solution across a magnetic field range of 0-10 Tesla.

Main Results:

• Achieved atomic-resolution imaging of graphite surfaces with low drift rates.
• Demonstrated the STM's immunity to magnetic fields by imaging graphite under sweeping fields up to 10 Tesla.
• Obtained sub-molecular resolution images of active antibodies and plasmid DNA in solution.

Conclusions:

• The developed liquid-phase STM is the first to operate effectively in high magnetic fields.
• This instrument opens new avenues for studying molecular and biomolecular behavior in solution under magnetic field influence.
• The STM is suitable for advanced research in chemical and biological sciences requiring high magnetic field conditions.