16 May 2018
The writing and deletion of magnetic Skyrmions is a fundamental step towards the fabrication of memory devices based on this promising spin configuration. Researchers at the Korea Institute of Technology have demonstrated the writing and deleting of isolated magnetic Skyrmions at room temperature in ferrimagnetic multilayer superlattice stacks using electrical currents.
7 May 2018
The spot size of a Fresnel Zone Plate lens is mainly determined by the zone widths of its outermost zone. It is therefore essential to fabricate zone plates with structures as small as possible for high-resolution X-ray microscopy. Researchers at the Laboratory for Micro- and Nanotechnology at the PSI have now developed Fresnel zone plates with zone widths well below 10 nm, down to 6.4 nm. These lenses are capable of pushing resolution in X-ray microscopy to the single-digit regime.
19 March 2018
In the week of March 18-23 PSI welcomes 20 PhD students and postdocs taking part in
the HERCULES 2018 school on Neutron and Synchrotron Radiation. They will attend
lectures and perform two days of practical courses at several beam lines of the Swiss
27 February 2018
Classical theory predicts that supersaturated carbonate solutions consist mostly of ions and ion pairs, with a small number of larger clusters present in the solution. The population of the different sized clusters in a solution is solely defined by the cluster’s size dependent Free Energy. If clusters are large enough they serve as nucleation germs for a new solid phase. The nucleation occurs once the surface free energy barrier posed by the new solid-liquid interface is overcome by the free energy win from bulk phase growth. However, for calcium carbonate solutions, this classical view has been challenged by the emergence of non-classical theories. In a novel experiment, using synchroton X-ray absorption spectroscopy, the molecular structure around the solvated calcium ion in dilute supersaturated calcium carbonate solutions was probed in situ. The results obtained definitively show that supersaturated calcium carbonate solutions are dominated by ions and ion pairs. The presence of larger oligomers as predicted by non-classical theories was not detected. Moreover, predictions from independent theoretical calculations on the structure of supersaturated calcium carbonate solutions were in congruence with the experimental results. As a consequence, it is quite clear that the nucleation of calcium carbonate follows a classical pathway.
29 January 2018
Using a unique set of well-defined silica-supported Ni nanoclusters (1–7 nm) and advanced characterization methods it was proved how structure sensitivity influences the mechanism of catalytic CO2 reduction, the nature of which has been long debated.