Keysight 5500 SPM
User’s Guide
7
Additional Imaging Modes
Scanning Tunneling Microscopy (STM)
Lateral Force Microscopy (LFM)
Dynamic Lateral Force Microscopy (DLFM)
Force Modulation Microscopy (FMM)
Electrostatic Force Microscopy (EFM)
One of the primary advantages of the Keysight 5500 SPM is that it
allows you to perform many different imaging modes with the same
basic hardware. Most of the modes presented in this chapter are based
on Contact Mode or AC Mode imaging, so be sure that you have read
the information in
before
proceeding with this chapter.
Scanning Tunneling Microscopy (STM)
In STM, a bias voltage is applied between a sharp, conducting tip and
the sample. When the tip approaches the sample, electrons “tunnel”
through the narrow gap, either from the sample to the tip or vice versa,
depending on the bias voltage. The tunneling current is held constant
throughout the scan. Changes of only 0.1 nm in the separation distance
cause an order of magnitude difference in the tunneling current. The
CAUTION
Some nose assemblies, such as the two-piece nose assemblies and
CSAFM nose assembly, are not sealed and should never be used for
imaging in liquid. Be sure to use only approved nose assemblies for
imaging with the liquid cell.