Large helium nanodroplets splash like water upon floor collisions

While working with helium nanodroplets, scientists on the Department of Ion Physics and Applied Physics led by Fabio Zappa and Paul Scheier have come throughout a shocking phenomenon: When the ultracold droplets hit a tough floor, they behave like drops of water. Ions with which they have been beforehand doped thus stay protected on influence and should not neutralized.

At the Department of Ion Physics and Applied Physics, Paul Scheier’s analysis group has been utilizing helium nanodroplets to review ions with strategies of mass spectrometry for round 15 years. Using a supersonic nozzle, tiny, superfluid helium nanodroplets might be produced with temperatures of lower than one diploma Kelvin. They can very successfully be doped with atoms and molecules. In the case of ionized droplets, the particles of curiosity are connected to the costs, that are then measured within the mass spectrometer. During their experiments, the scientists have now stumbled upon an fascinating phenomenon that has basically modified their work. “For us, this was a gamechanger,” says Fabio Zappa from the nano-bio-physics workforce. “Everything at our lab is now done with this newly discovered method.” The researchers have now revealed the outcomes of their research in Physical Review Letters.

A shocking phenomenon

When charged particles are fired at a metallic plate, the particles are usually neutralized by the various free electrons on the metal surface. They can then not be measured within the mass spectrometer. But when the ions are packed in a helium nanodroplet, they continue to be protected on influence and fly off in all instructions with a number of weakly certain helium atoms. “The ions are apparently protected by the helium,” Zappa says. He would not but totally perceive the underlying mechanism. “But there is some evidence that the helium loses its superfluid property before impact and then behaves like a liquid, splashing away from the surface and only then partially evaporates.” Another potential cause might be that the primary droplets evaporate on the floor, forming a layer of fuel that slows down subsequent droplets and, on this means protects them from evaporation. Only additional investigations will present if one in every of these explanations is appropriate or if there are different causes. The undeniable fact that this methodology additionally works with unfavorable ions, that are usually very fragile, signifies to the scientists a robust impact of the beforehand unknown phenomenon.

Nanotechnology advantages

With this discovery, Paul Scheier’s workforce not solely improved their very own measurement methodology, but additionally gained essential insights for different analysis teams that, for instance, take care of the deposition of nanoparticles on surfaces. “Metal nanoparticles are a great example of this,” Scheier recounts. “In many modern technologies, metal nanoparticles are found that have very specific properties.” The undeniable fact that the technology of such nanofilms can typically be very inefficient is also associated to the phenomenon now found in Innsbruck.