Scientific Highlights
Liquids in narrow spaces
How does spatial confinement affect the microscopic structure of liquids?
This is a question which is receiving increasing attention from condensed matter physicists. Liquids are characterized by a short-ranged, so-called local structure, and it has been predicted theoretically about 25 years ago that confinement induces anisotropy in the local structure, and hence many properties, of liquids.
Femtosecond dynamics of an antiferromagnetic phase transition
We report on the ultrafast dynamics of magnetic order in a single crystal of CuO at a temperature of 207 K in response to strong optical excitation using femtosecond resonant x-ray diffraction. In this experiment performed at the LCLS X-ray free electron laser at Stanford a femtosecond laser pulse induces a sudden, nonequilibrium increase in magnetic disorder.
A close look at correlated electrons in heavy-fermion metal through ARPES
Showing astonishing properties like magnetism, superconductivity, Kondo and heavy-fermion (HF) behavior, rare-earth intermetallic compounds have been at the forefront of modern solid state physics for many years. Most of these properties are related to a delicate interplay between the partially filled 4f-shell and conduction electrons.
Vertical Emittance of the SLS Storage Ring
On the 6th of December 2011 the vertical emittance of the SLS storage ring could be reduced to a world record low value of 1pm rad. The vertical beam size in the short straight sections of the SLS is then only 3 micron (rms). This was achieved through vertical re-alignment of the magnet girders with 400mA stored beam and fast orbit feedback running, as well as through application of several different methods of coupling suppression using 36 skew quadrupoles. High resolution profile monitor utilizing vertically polarized component of synchrotron radiation allowed precise determination of the beam size.
New insights into the cell’s protein factory
Eukaryotic ribosomes are among the most complex cellular machineries of the cell. These large macromolecular assemblies are responsible for the production of all proteins and are thus of pivotal importance to all forms of life. Two independent research groups at the ETH Zürich and the Institute of Genetics and Molecular and Cellular Biology in Strasbourg have obtained new insights into the atomic structure of the eukaryotic ribosome. The results have been published in the journal Science.
Bilayer manganites reveal polarons in the midst of a metallic breakdown
The origin of colossal magnetoresistance (CMR) in manganese oxides is among the most challenging problems in condensed- matter physics today. The true nature of the low-temperature electronic phase of these materials is heavily debated. By combining photoemission and tunnelling data, we show that in the archetypal bilayer system La2-2xSr1+2xMn2O7, polaronic degrees of freedom win out across the CMR region of the phase diagram.
Influence of Methyl Halide Treatment on Gold Nanoparticles Supported on Activated Carbon
Gold particles supported on carbon when subjected to a flow of methyl iodide or bromide redisperse from large ensembles to single atoms and/or dimers of gold. Methyl halide oxidizes gold leading to gradual particle dissolution. The process could be carried out at temperatures as low as 50 °C. The excess of halide could be removed by a post-treatment of the material with 1%H2O/H2, which does not influence the metal dispersion. This remarkable transformation opens the possibility of re-activating gold catalysts that lost their performance due to metal particles sintering.
Direct Observation of Local Mn-Mn Distances in the Paramagnetic Compound CsMnxMg1-xBr3
We introduce a novel method for local structure determination with a spatial resolution of the order of 0.01 Å. It can be applied to materials containing clusters of exchange-coupled magnetic atoms. We use neutron spectroscopy to probe the energies of the cluster excitations which are determined by the interatomic coupling strength J.
CCN formation mechanism in lower troposphere needs revision
Atmospheric aerosols exert an important influence on climate1 through their effects on stratiform cloud albedo and lifetime and the invigoration of convective storms. Model calculations suggest that almost half of the global cloud condensation nuclei in the atmospheric boundary layer may originate from the nucleation of aerosols from trace condensable vapours, although the sensitivity of the number of cloud condensation nuclei to changes of nucleation rate may be small. Despite extensive research, fundamental questions remain about the nucleation rate of sulphuric acid particles and the mechanisms responsible, including the roles of galactic cosmic rays and other chemical species such as ammonia. Here we present the first results from the CLOUD experiment at CERN.
Investigation of a new method for the diagnosis of cancer in breast tissue
Collaboration between research, hospital and industry aimed at transferring innovative procedure into daily practice.