Scientific Highlights
Lattice dynamics of α-cristobalite and the Boson peak in silica glass
This work marks a decisive step in the solution of the longstanding problem understanding the origin of the Boson peak in silica glass. The investigation by means of diffuse and inelastic x-ray scattering and lattice dynamics calculations from first principles allow for a direct comparison of the atomic motion in crystalline silica polymorphs and silica glass. The article was selected to illustrate the cover page of Journal of Physics: Condensed Matter, Vol. 27, Nr. 30.
Lattice dynamics of α-cristobalite and the Boson peak in silica glass
B. Wehinger et al., J. Phys.: Condens. Matter 27, 305401 (2015). This work marks a decisive step in the solution of the longstanding problem understanding the origin of the Boson peak in silica glass. The investigation by means of diffuse and inelastic x-ray scattering and lattice dynamics calculations from first principles allow for a direct comparison of the atomic motion in crystalline silica polymorphs and silica glass.
Candidate Quantum Spin Liquid in the Ce3+ Pyrochlore Stannate Ce2Sn2O7
We report the low-temperature magnetic properties of Ce2Sn2O7, a rare-earth pyrochlore. Our suscep- tibility and magnetization measurements show that due to the thermal isolation of a Kramers doublet ground state, Ce2Sn2O7 has Ising-like magnetic moments of ∼1.18 μB. The magnetic moments are confined to the local trigonal axes, as in a spin ice, but the exchange interactions are antiferromagnetic.
Umbrella MoU Signed by 14 Parties
The Memorandum of Understanding of the Umbrella Collaboration was signed by 14 parties: ALBA, DESY, Diamond Light Source Ltd, Elettra, EMBL Heidelberg, ESRF, European XFEL, HZB, ILL, Instruct Academic Services Ltd, KIT, PSI, STFC and SOLEIL.
In Situ Serial Crystallography Workshop at the SLS
The Macromolecular Crystallography group at SLS is organizing a three days workshop on in situ serial crystallography (http://indico.psi.ch/event/issx) between November 17 and 19, 2015. It will be dedicated in the presentation of a novel method facilitating the structure determination of membrane proteins, which are highly important pharmaceutical targets but are difficult to handle using 'classical' crystallographic tools. Designed for 20 Ph.D. students, postdocs and young scientists from both academia and industry, the workshop will consist of introductory lectures, followed by hands-on practicals on in meso or lipidic cubic phase (LCP) crystallization, on in situ serial crystallography data collection using a micro-sized beam and on data processing.
New insight into receptor signalling
A team of 72 investigators across 25 institutions including researchers from the Paul Scherrer Institut obtained the X-ray structure of a rhodopsinàarrestin complex, which represents a major milestone in the area of G-protein-coupled-receptor (GPCR), a protein family recognized in the award of the 2012 Nobel Prize in Chemistry.
Terahertz laser light focused to the extreme
There are limits to how short a flash of light can be – in both time and space. Researchers from the Paul Scherrer Institute (PSI) have now succeeded in reaching these physical limits and producing the smallest possible flash. To do so, they used terahertz light, which is physically related to visible light or radio waves, but differs in its wavelength.
Nanoscale switch for vortex polarization mediated by Bloch core formation in magnetic hybrid systems
Vortices are fundamental magnetic topological structures characterized by a curling magnetization around a highly stable nanometric core.
Element-Specific X-Ray Phase Tomography of 3D Structures at the Nanoscale
Recent advances in fabrication techniques to create mesoscopic 3D structures have led to significant developments in a variety of fields including biology, photonics, and magnetism. Further progress in these areas benefits from their full quantitative and structural characterization.
Beating the Stoner criterion using molecular interfaces
Only three elements are ferromagnetic at room temperature: the transition metals iron, cobalt and nickel. The Stoner criterion explains why iron is ferromagnetic but manganese, for example, is not, even though both elements have an unfilled 3d shell and are adjacent in the periodic table: according to this criterion, the product of the density of states and the exchange integral must be greater than unity for spontaneous spin ordering to emerge.