Variable Temperature STM

The LPM Variable Temperature STM allows the operator to change the temperature in-situ , so during scanning over an atomically resolved area. This can even be done whilst scanning at speeds beyond 1 ms per scan line. The unique specs make that the VT-STM the perfect instrument to reveal dynamic processes: change the temperature by more than 250º and study a single atomically resolved area during CVD, assembly, melting, growth, etc.

A unique feature of this STM is that when the temperature is ramped, thermal expansion of the sample is restricted to a small unidirectional shift, dependent only on the sample material. Drifts during a temperature ramp are much lower in our design than in alternative designs where a specific nm-size area can be brought back into view after a thermal ramp. Another benefit is that a temperature range of more than 750 K can be covered without the need for coarse adjustments of the sample/probe.

The design allows for flexible sample and scanner (including tip) manipulation using a single wobble stick. The optical access to the sample surface and the protection of the scan piezo allow for in situ sample treatments, even while scanning (e.g. ion-bombardments or deposition).

Using our conical scan piezo element, the scan speed can be further increased. A line speed of 100 µs/line can be achieved, even on stepped surfaces, and with full resolution (256 x 256 pixels).

The eddy-current damping system ensures good vibration isolation, such that surfaces can be atomically resolved. The STM can be supplied complete with a vacuum chamber and local sample and scanner handling, or as a single STM on a CF200 flange.

Applications

  • Dynamic phenomena: diffusion of steps, kinks, and vacancies
  • Creation and activation energy studies
  • Self-assembly processes
  • Nucleation, growth, melting
  • Segregation

Benefits

  • Real variable temperature instrument due to the unique thermal drift compensated design: keep scanning the same atoms while the temperature is changed over 250°
  • Demonstrated: scanning from 300 K to 1050 K without coarse readjustments
  • Excellent vibration isolation and damping

Specifications

  • Thermal drift: < 0.15 nm/min (x,y), 0.05 nm/min (z)
  • Thermal shift: < 15 nm/K (lateral)
  • Thermal range: RT - >1000 K (~35 K - >1000 K with cooling option)
  • X-Y range: 3.5 µm
  • Excellent optical access to tip/sample
  • High speed scanning
  • Tip/sample exchange

Additional information and documentation




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