Ultra high resolution atomically resolving imaging via SPM microscopy
As of 2023 by means of attaching a -CO group to the tip of a stiff AFM cantilever
it is possible to resolve not just atoms but even atomic substructures.
That is: Details of he shape of inter-orbital steric repulsion.
Contents
Unexpected shapes of surface repulsion
In cases where metal electron gas is involved repulsion can behave in rather non-intuitive ways.
Like e.g. an atom behaving like a ring in the shape of it's repulsion.
(wiki-TODO: find and link relevant video and paper)
(wiki-TODO: Find and link relevant paper about great advance in chemical contrast)
High resolution of AFM as a unexpected surprise
Earlier STM was considered more highly resolving because of the tunneling current featuring rapid exponential drop-off.
Also the manufacturing method of etching PtIr tips may lead to sharper tips than when etching silicon or silicon nitride (to verify).
As such the AFMs with one big leap overtaking STMs (via the -CO pickup trick) may have come as a bit of a surprise.
Singleatomic manipulation mostly done by STM instead with more limited resolution
Though the methods used for this high resolution are of very different kind to the ones with which
manipulation of individual atoms have been shown. (wiki-TODO: investigate details)
Related
- 2022 video Franz Giessibl | Chemical Bonds to Atoms Resolved by Subatomically Resolved Atomic Force Microscopy (non intuitive shapes of repulsion)
- 2017 paper Ultrahigh-resolution imaging of water networks by atomic force microscopy
- 2014 video lecture on nc-AFM nanoHUB-U Fundamentals of AFM L1.3: Tip-Surface Interactions (Non-Contact) - Physical Models
External links
- Wikipedia: Non-contact atomic force microscopy
