Low-temperature scanning tunneling microscope

Trade name
Technical description

The scanning tunneling microscope belongs to the family of scanning probe microscopes and allows us to study surfaces with atomic resolution. It works based on the quantum phenomenon of electrons tunneling through a barrier that they could not overcome in classical mechanics. The probe (in the form of an extremely sharp metal tip) is brought close to the conductive sample at a distance of several angstroms. Under these conditions, the system registers the tunnel current, which depends on the distance between the tip and the sample and the Local Density Of States (LDOS) around the Fermi energy. By scanning point by point and line by line, a two-dimensional image of the tested surface is obtained. This image usually cannot be directly interpreted as topography; it requires a deeper analysis often combined with additional measurement methods and/or numerical simulations. An extension of the capabilities of this microscope is also the performance of scanning tunneling spectroscopy (STS) measurements. They provide information about the local electronic structure of the sample, occupied and unoccupied states close to the Fermi energy. All the above-mentioned measurements can be performed in a wide range of temperatures, see: "measuring possibilities". The STM system is extended with UHV chamber for samples preparation.

Conditions for providing infrastructure

Equipment is available in accordance with the Regulations for the Use of ACMiN's Research Infrastructure.

Type of accreditation / certificate:
Not applicable
Access type
Research capabilities

Imaging of the 'topography' of conductive surfaces of samples with atomic resolution.

Determine current-voltage characteristics (I-V, dI/dV).

Last update date
Aug. 30, 2023, 12:46 p.m.
Year of commissioning
Measurement capabilities

Coarse XY positioning: 5 mm x 5 mm

Scan range: 5 μm x 5 μm (X, Y)

Minimum resolution: 0.5Å (X, Y) and 0.1Å (Z)

Thermal drift: <1 Å/min

Sample temperatures: ~50 K (LHe) or ~120 K (LN2) to ~1500 K

Maximum sample size: 10mm diameter

scanning tunneling microscope
scanning tunneling microscope