Presenters

Chemical Bonds to Atoms Resolved by Subatomically Resolved Atomic Force Microscopy

  • People say that scanning tunneling microscopy is dead.
  • What do we need to do to keep the music playing?
  • Franz studies the differences between atomic force and scanning tunneling microscopy.
  • Atomic forces are concealed behind much stronger van der waal’s forces. They are not monotonic – they start out attractive and then turn repulsive. These forces are hard to measure. One solution is to use quartz for the construction of microscopy tips. It’s possible to get much clearer resolution via scanning tunneling microscopy than atomic force microscopy, without interference from the secondary layer of atoms in the microscope tip.
  • Replacing quartz with silicon yielded atomic and subatomic resolution. As tip development progresses, it becomes apparent that the tip itself needs to be probed. A method called COFI – carbon-monoxide front atom identification – can be used to probe the tip.
  • Giessibl goes on to discuss imaging of single atoms of copper, iron, and silicon using both atomic force and scanning tunneling microscopy, and the resolution limitations of each.

Challenges

  • Measuring atomic forces – Parsing out atomic forces from van der waal’s forces is difficult – there is a low signal to noise ratio.
  • Create a tip that works at ambient conditions – This would massively accelerate progress by 3D imaging at the atomic scale
  • Increase Time resolution – combining with laser experiments