Equipment Catalog

The Low-Temperature STM/AFM facility provides a state-of-the-art, ultra-high vacuum (UHV) scanning probe microscope for atomic-scale imaging, HR-AFM services for molecular structure imaging, spectroscopy, and manipulation at cryogenic temperatures.

The system operates at 4.2 K (down to 2.2 K or elevated temperatures up to ~300 K for specialized experiments.

Key Capabilities:

• High-resolution STM and nc-AFM imaging at the atomic and molecular scale with dedication for HR-AFM of molecules.
• Tunneling spectroscopy (STS)
• Single-atom and molecule manipulation
• RF-enabled measurements up to 40 GHz, allowing for ESR and RF-STM (*)
  

Dedicated HR-AFM capability for molecular structure imaging:

The instrument is specifically optimized for high-resolution AFM (HR-AFM), enabling direct visualization of molecular backbones, bonding configurations, and intramolecular structure. This makes it particularly well suited for studies of organic molecules (e.g., PAHs).

Instrument Details:

• Latest-generation (2025) Createc LT-STM/AFM
• Q-Plus sensor (~30 kHz) with FIB-shaped PtIr tip; or regular STM tip
• RF access with near-junction antenna (up to 40 GHz) and via sample contacts (*)
• Static magnetic field option (out of plane) up to ~ 0.4 T (*)
• Ultra-stable cryogenic environment for low drift and high precision
• Gxsm4 control software with Python-based automation
• Open data format (HDF5 container with NetCDF4 data structures)

Sample Support & Preparation:

• UHV preparation chamber with heating and cooling stages
• Automated Ar sputter/anneal cleaning for single-metal crystal cleaning over night
• Gas dosing (1/4” VCR hookup) and evaporation access via fast exchange ports (2-3/4” CF port)
• Capability for low-temperature, low-coverage molecule deposition/transfer from a miniature quantity of molecule material (sub micro-grams)

Industry standard flag-style sample holders are used (up to ~10 × 10 mm usable area, ~4 mm max height).

A range of atomically flat metal substrates (e.g., Au(111), Ag(111), Cu(111)) is available to support molecular imaging experiments.

Sample Requirements:

• Electrically conductive at cryogenic temperatures (~4 K)
• Clean, atomically flat surfaces strongly preferred
• Full disclosure of all materials and preparation procedures is required

Notes for Users:

This instrument is optimized for small-area, ultra-high-resolution measurements, with a strong emphasis on molecular structure analysis using HR-AFM and advanced RF-enabled techniques.

Due to constraints on sample geometry, motion range, and cleanliness, etc., not all samples are suitable. Users are encouraged to contact staff early to discuss feasibility.