USM1800 Cryogen-Free Low Temperature UHV Scanning Probe Microscope

PDF SPM System Specs. Published Papers

Realization of STM & AFM with atomic resolution below 6 K by mechanical refrigeration
Continuous cooling for long periods of time without the use of scarce liquid helium
STM-TERS is now available【New】

Image of USM1800

The closed-cycle USM1800 LT UHV SPM is now part of the UNISOKU SPM product family! The USM1800 provides sample temperatures below 6 K, and the cryogen-free cooling system achieves ultimate SPM performance at low temperature while allowing interruption-free measurement conditions.

Features

  • Sample temperature below 6 K (when optical window shielding is closed)
  • State-of-the-art SPM platform with atomic resolution imaging (qPlus® AFM is available as an option)
  • Optical access and in-situ deposition capabilities (inertial-driven lens stages on the SPM platform are available as an option)
  • The sample holder is available in either the conventional bayonet type or the flag type.

    • Applications

    • Replacement of a liquid-helium-based low-temperature SPM system
    • Observation of quasi-particle interference patterns by tunneling spectral mapping
    • Observation of surface adsorption structure using in-situ deposition capabilities
    • Studies of photo-induced phenomenon in combination with simultaneous SPM measurements

    Schematic view of the USM1800 system

    3D model of sample/probe transfer

    Cooling performance

    Cooling time: <6 K in 24 hours


    Cooling performance Cooling time: <6K in 24 hours

    Temperature stability @ 5.2 K


    Cooling performance Temperature stability @ 5.2K
     

    Long-term stability of STM

    Long-term STM images of Si(111) surface @T = 4.8 K


    Long-term STM images of Si(111) surface @T = 4.8 K
     

    Tunneling current noise spectrum


    Nc-AFM NaCl atomic image at 6K sample

    Superconducting gap of Pb


    STM Au(111) atomic image at 5.6K sample
     

    Nc-AFM NaCl atomic image at 6 K


    Nc-AFM NaCl atomic image at 6K sample

    Sample: NaCl (100)
    AFM sensor: qPlus®
    Amplitude: 200 pm
    Frequency shift: -13 Hz

    STM Au(111) atomic image at 5.6 K


    STM Au(111) atomic image at 5.6K sample

    Sample: Au(111)
    Scan size: 7 nm x 7 nm
    Bias voltage: +5 mV
    Tunnel current: 1 nA

     

    TERS at 8 K【New】


    Nc-AFM NaCl atomic image at 6K sample

     
     
    Specifications
    SPM structure Tip scanning type
    Coarse positioning for X,Y (ø 1 mm) and Z (5 mm)
    Scan range 1 um × 1 um at 6 K
    Sample holder Bayonet style holder, Flag style holder
    (DC heating, EB heating, cleaving)
    USM1800 Sample holder image
    Temperature <6 K
    1.5 year in each for Maintenance
    (Pulse tube refrigerator)
    Options Internal optical lens stages with 3D coarse positioning (NA ～ 0.25)
    Tuning Fork NC-AFM
    Chamber structure Includes SPM observation chamber, preparation chamber, and loadlock chamber.
    In-situ UHV sample/probe holder transfers
    Laboratory Requirements
    Recommended laboratory area Floor space: 4 m × 4 m, Ceiling height: > 2.8 m
    Floor vibration level < 1 μm/s (rms) below 5 Hz
    < 3 μm/s between 5-10 Hz
    < 5 μm/s above 10 Hz
    Preparation of equipment •Cooling water
    •Three-phase electric power


    PDF SPM System Specs.