Cryogen-Free Cooling Combined with Scanning Probe Microscopy in an Ultra-High Vacuum High Field environment

We merged cryogen-free operation with scanning probe microscopy (SPM) in our ground-breaking ultra-high vacuum (UHV) system reaching low temperatures (4K) and high magnetic fields (9T). This achievement is owed to the creation of a unique internal vibration isolator (Patent Application US17/996,246) and custom probe head (U.S. Patent No. 11,474,127), which reduced the vibration level of the cryostat pulse tube to operate SPMs, solving the noise problem of typical cryogen-free systems. The modular design of our probe head accommodates interchangeable probes, such as STM, AFM, and MFM. Conditioning of sample and probe is incorporated into the UHV system, particularly ion sputtering, e-beam film deposition, exfoliation, and heat treatment. The compact SPM head is transferable about the entire system, allowing for sample and probe insertion at room temperature with optical access. Transport of the SPM to the cryogen-free cryostat is enabled by a novel low-profile vertical transfer mechanism (Patent Application PCT/US2019/027929). Incorporating all these capabilities into one instrument permits exploration of nano-scale characterization of low dimensional systems in an ultra-clean environment with controlled temperature and magnetic field.