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Nanoparticle Stability //

Penetration of Thin Fullerenes

P

hysicists from the TU Dortmund, the University of Freiburg and the Fraunhofer Institute for Me-

chanics of Materials IWM, Germany, reveal a new

mechanism important for the stability of nano-

composites. Physicists observed that a double layer of spherical C60 carbon-molecules, called fulleren- es, is an ideal substrate for these microscopic parti- cles.

The properties of nanoparticles often differ from those of a large piece made of the same material. By tuning the size and composition of the nanoparticles, one can “tailor” their chemical, optical or magnetic properties, and obtain features different from any bulk material. But for an application of this potential in the fields of catalysis, magnetic storage technology or optoelectronics, one has to fix the nanoparticles on surfaces or in matrixes. During this process the interaction with the surface or matrix at the worst destroys the unique properties of the nanoparticles.

Therefore it is important to develop techniques for a “gentle” yet secure fixation of nanoparticles. This was now achieved by the research team, who deposited the particles on a layer of spherical C60 carbon- molecules, called fullerenes, and investigated their properties.

They showed that a double layer of fullerenes on a metal surface is an ideal substrate for the fixation of

nanoparticles. The size and shape of the particles sta- yed unchanged for days even at room temperature, which is “hot” for nanoscale processes.

On a single layer of fullerenes, however, the parti- cles shrank fast and disappeared within a few hours. Using atomic simulations this was traced back to temporary contacts bridging the fullerene layer and transporting atoms from the nanoparticles to the sup- porting metal surface.

Stefanie Duffe, Niklas Grönhagen, Lukas Patryarcha, Bene- dikt Sieben, Chunrong Yin, Bernd von Issendorff, Michael Moseler and Heinz Hövel: Penetration of thin C60 films by metal nanoparticles“ In: Nature Nanotechnology AOP, April 04, 2010, DOI:10.1038/NNANO.2010.45: http://dx.doi.org/10.1038/NNANO.2010.45

10-04 :: April 2010