What exactly happens when highly charged particles hit solid bodies is of great importance in material analysis, according to a broadcast from the university on Monday. For this purpose, the Viennese researchers snatch up to 20 to 40 electrons from atoms in the laboratory. These ions then quasi starve for supplies.
Experiment with graph
How these particles are supplied with new electrons in order to become neutral again has not yet been directly observed. “We knew that this process had to be very fast, because a very thin layer of material is enough to completely neutralize ions,” says first author Anna Niggas from the Institute for Applied Physics.
This is how the scientists came up with the idea of using graphene, a material made up of only one layer of carbon atoms, as a basic material for their experimental set-up . “We examined single, double, and triple layers of graphene. So you can see step by step, atomic position by atomic position, how exactly the charged ions change, ”says physicist Richard Wilhelm.
Laws of Neuralization
The researchers bombarded these different layers with the ions at different speeds. It turned out that the neutralization process follows a simple principle: the more time the electron-hungry ion spends near the electron provider, carbon, the faster its state normalizes.
“If you take into account that the ions come into contact with carbon atoms two or three times as long on their journey through two or three graphene layers as in a single graphene layer, then simple formulas explain how quickly the ions capture electrons and change their state of charge, ”niggas said.