SPM with high magnetic fields and low temperature

  Laboratory of Scanning Probe Microscopy with high magnetic fields and low temperature

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    SPM_HM  This laboratory offers the possibility of combining probe measurements with low temperatures and a high vector magnetic field.
      The SPM with high magnetic fields and low temperature is especially designed for combination of local probe and magneto-transport measurements as, for example, scanning gate microscopy.
Therefore, it runs research lines oriented towards low temperature magnetism, transport through nanodevices, spintronics, and superconductivity.
            The instrument is composed by a large liquid helium cryostat holding a vertical bore superconducting magnet reaching 8 T (one axis) / 2 T (2D vectorial) magnetic field and a variable temperature controller (2 K-300 K).
The equipment has a quick load facility, allowing an easy sample replacement. The system is also equipped with two different piezos in order to get the best features in resolution and stability, and a low noise voltage amplifier keeping the conditions to get the best signal/noise ratio.


What kind of information can be obtained with this instrument?

These features allow performing many of the STM/AFM related techniques:
  • Surface morphology. Topography with resolution below 1 nm.
  • Electrical conductivity (c‐AFM). Quantitative local electrical resistance measurements.
  • Local electrical potential (KPM). Qualitative measurements of local charge distribution.
  • Magnetic properties (MFM). Magnetic properties analysis under magnetic fields.
  • Piezo-electric properties (PFM). Using the tip as electrode and deformation sensor.
  • Thermal dependence. Capacity to measure in the 2 to 500 K range.
  • Topography based in low vacuum Scanning Tunnel Microscopy (STM).

Sample requirements

  • The sample should be immobilized onto a flat substrate
  • The sample should exhibit a roughness lower than the range of the piezo scanner.
  • The size of the sample should be small enough to fit inside of the microscope, around 1cm2 and a maximum thickness of 0.5 cm.
  • The sample should be compatible with low temperature and vacuum conditions.

Technical Specifications

  • AFM/MFM head with interferometric sensor.
  • STM/Tuning Fork head.
  • Variable temperature insert (1.5 K-300 K) cryostat.
  • 8 T (vertical) and 2 T (in-plane) superconducting magnet, that combined with a rotating platform allows to apply vector fields in three dimensions.
  • Compatible chip carrier with dual-beam and pulsed field facilities.


Topography and magnetic signal from a permalloy nanowire

Topography and piezoresponse map from a piezoelectric material thin film