Research Highlights 2012

Dodecagonal Quasicrystals

Phase-contrast imaging performed on an aberration-corrected scanning transmission electron microscope (STEM) represents a means to characterize the structure of dd-(Ta,V)_1.6Te phases. The basic (Ta,V)₁₅₁Te₇₄ clusters can be visualized with high resolution with the image contrast depending on defocus and specimen thickness like in HRTEM. In thin areas, the projected crystal potential is basically imaged and square-triangle tilings can be derived in which each vertex corresponds to a cluster center (an example is marked by arrow in the image).

The Structure of Dodecagonal (Ta,V)_1.6 Te Imaged by Phase-Contrast Scanning Transmission Electron Microscopy
F. Krumeich, E. Müller, R.A. Wepf, M. Conrad, C. Reich, B. Harbrecht, and R. Nesper
J. Solid State Chem. 194 (2012) 106-112 DOI

Behaviour of Nanoparticles in a Waste Incineration Plant

The persistence of nanoparticles during waste combustion was probed by introducing nano-CeO₂ (image) into the waste or the gas stream exiting the furnace of a muncipal waste incineration plant. The analysis of the residues show the presence of the unaltered nanoparticles in the slag and fly ash. Thus, although the nanoparticles are efficiently filtered from the cleaned gas, they still remain in the solid residues which has to be taken care of before deposition.

Persistence of Engineered Nanoparticles in a Municipal Solid-Waste Incineration Plant
T. Walser, L. K. Limbach, R. Brogioli, E. Erismann, L. Flamigni, B. Hattendorf, M. Juchli, F. Krumeich, C. Ludwig, K. Prikopsky, M. Rossier, D. Saner, A. Sigg, S. Hellweg, D. Günther, and W. J. Stark
Nature Nanotechn. 7 (2012) 520-524 DOI