Sinking gold atoms filmed with real time nano-imaging
for the first time, to film gold atoms sinking into a surface in
real time.
Researchers at Kavli Institute of Nanoscience, Delft University of Technology, Netherlands, used a High Resolution Electron Microscope (HREM) to film a small group of gold atoms on a gold surface.
This was the first time the atom-sinking phenomenon - called collective transport - had been observed in real time, according to Professor Henny Zandbergen. The results were then validated and certified in collaboration with Princeton University, US. The film can be seen here.
On its own, observing the collective transportation of gold atoms on a surface provides important information for people constructing thin layers. However, it also illustrates the rapid progress that is currently being made by real-time nano-microscopy or nano-imaging, which is becoming increasingly accurate and faster.
Within a few years, the technology could open up a wealth of possibilities for industry and the medical world, by allowing scientists to follow biological processes very realistically.
A short film of the research shows how a group of gold atoms collectively sank into the underlying layer of atoms and became squeezed between other atoms. Later on, the extra atoms disappear, "as if a string of beads has been pulled away lengthwise."
According to Professor Zandbergen, the way in which the atoms arranged themselves in the underlying layer and the movement of the dislocation is, in principle, an attractive way of transporting materials from the upper layer to the underlying layer and also within the underlying layer.
Normally, before an atom can 'hop' from one layer to the underlying layer, certain energy barriers exist. But such barriers do not exist with this manner of transport. The findings of this research project clearly indicate that when people are modelling the (industrial) production of thin layers, they must also consider this type of collective processes.
It is now possible to observe the movements of atoms in real-time, and this allows the position of the atoms to be determined with great precision (approximately 0.01 nm). So far, this has primarily been observed under laboratory conditions. But soon live nano-imaging could take the next step to realistic or real-life conditions.
The research was done under vacuum but Zandbergen said in an interview that his team were now researching ways of repeating the experiments under more realistic conditions - for example, under gas pressurised to atmospheric levels.
There are two stumbling blocks to overcome before the technology can be used to assess biological materials in realistic conditions. First, a cell is too thick and gives blurred images and so must be sliced very thinly to give sharp images. The sample is also frozen.
A second problem is that it is not known whether the electron beam will interact with the biological sample and skew any reactions.
Zandbergen's technology differs from others in that the whole process is conducted in a 'nano-reactor' where environmental conditions can be more easily controlled. This enables more efficient research with faster results.
