Recherche sur le Covid-19

Au PSI, plusieurs projets se consacrent à des questions de recherche importantes autour du coronavirus Sars-CoV-2 et des maladies qui en résultent. Nous vous informons sur les activités et les projets, par exemple sur les analyses de tissus pulmonaires, sur la production de protéines et d'anticorps ou sur les idées de nouvelles recherches sur le Covid-19.

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Redox

New class of substances for REDOX chemistry

The compounds known as ‘pyrazinacenes’ are simple, stable compounds that consist of a series of connected nitrogen-containing carbon rings. They are suitable for applications in electrochemistry or synthesis, as the researchers describe in the science journal Communications Chemistry. They were first designed, synthesized and chemically characterized in solution by the Hill team and carefully investigated by Scanning Tunneling Microscopy and Surface Chemical Analysis. The compounds have been shown to reversibly release and accept electrons and arrange themselves differently depending on the oxidation state. Interestingly, the oxidation and reduction reactions of the pyrazinacenes are not only affected by a chemical impulse, but can also be stimulated by light so they can be considered photo-redox active.

 

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Hercules School 2021 at PSI

During the week of March 15 – 19, we had the pleasure to welcome 20 international PhD students, PostDocs and assistant professors at PSI, taking part in the first virtual Hercules School on Neutrons & Synchrotron Radiation.

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Important elementary reactions of lignin catalytic pyrolysis revealed

To develop sustainable lignin valorization strategies, a solid understanding of the underlying reaction mechanism is critical. By detection of highly reactive and elusive intermediates, new light could be shed on one of the most basic elementary reactions in lignin catalytic fast pyrolysis.

Ye et al

Observation of novel charge ordering and spin reorientation in perovskite oxide PbFeO3

PbMO3 (M = 3d transition metals) family shows systematic variations in charge distribution and intriguing physical properties due to its delicate energy balance between Pb 6s and transition metal 3d orbitals. However, the detailed structure and physical properties of PbFeO3 remain unclear. Herein, we reveal that PbFeO3 crystallizes into an unusual 2ap × 6ap × 2ap orthorhombic perovskite super unit cell with space group Cmcm.

 

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HERCULES SCHOOL 2021 AT PSI

During the week of March 15 – 19, we had the pleasure to welcome 20 international PhD students, PostDocs and assistant professors at PSI, taking part in the first virtual HERCULES SCHOOL on Neutrons & Synchrotron Radiation.

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2020 Highly Cited Researchers

Once more in 2020: Three LAC researchers were highly cited.

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Lehrberufe à la carte 2021 (abgesagt)

Am 20. Juni 2021 präsentiert das PSI seine 15 verschiedenen Lehrberufe. Auch das Schülerlabor iLab öffnet an diesem Sonntag seine Türen.

Swiss TecLadies

Berufe auch für Frauen!

Möchtet Ihr in eine, vielleicht fremde, Berufswelt eintauchen? Hier zeigen 4 junge Frauen in unterschiedlichen Berufen etwas aus ihrem Alltag, den Arbeitsplatz und über ihre Erfahrungen, die sie bereits in der Lehre am PSI gemacht haben.

Miao npj

Charge density waves in cuprate superconductors beyond thecritical doping

The unconventional normal-state properties of the cuprates are often discussed in terms of emergent electronic order that onsets below a putative critical doping of xc≈0.19. Charge density wave (CDW) correlations represent one such order; however, experimental evidence for such order generally spans a limited range of doping that falls short of the critical value xc, leading to questions regarding its essential relevance. Here, we use X-ray diffraction to demonstrate that CDW correlations in La2−xSrxCuOpersist up to a doping of at least x=0.21.

 

Thomas Jung

EPS Council

Thomas A. Jung has been elected as a delegate of the Associate Members of the European Physical Society. As a member he shall contribute to the reviewing of the activities of the Society, the annual accounts and to the discussion of future priorities and new activities.

Mobility

SCCER Mobility White Paper

New SCCER Mobility white paper on "Pathways to a net zero CO2 Swiss mobility system" is now online!

15th International Conference on Muon Spin Rotation postponed to 2022

Because of the coronavirus situation, the 15th International Conference on Muon Spin Rotation, Relaxation and Resonance (µSR2020) has been postponed to 2022, Aug 28 - Sep 02.

Information for SµS Users March 2021

Despite some limitations due to the Covid crisis the shutdown works at SµS have proceeded as planned so far, and the µSR instruments will be ready for operation on April 12, when HIPA operation is foreseen. However, as Swiss and foreign travel restrictions apply (https://www.psi.ch/en/useroffice/news/new-coronavirus-recommendations-for-travellers) it is not yet clear how user experiments at SµS will be conducted in the upcoming beam period. We will update information about this on our webpage as soon as possible.

Focusing of spinwaves from a deformed vortex core

Spin-wave emission from vortex cores under static magnetic bias fields

Employing time-resolved STXM imaging, researchers investigated the emission of spin waves from a magnetic vortex core. By applying static magnetic fields, the control of both the shape of the vortex core and of the spatial profile of the emitted spin waves could be demonstrated, allowing for the fabrication of field-tunable spin wave focusing elements.

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Buried moiré supercells through SrTiO3 nanolayer relaxation

The authors find that an annealing process can create a highly ordered network of two-dimensional line defects at the buried interface between a relaxed film and its substrate. The low dimensional network spacing is directly related to the lattice mismatch and can correspondingly be tuned by the choice of substrate.

12th Meeting of the European MELCOR and MACCS User Group

NUBIKI Nuclear Safety Research Institute as a WEBINAR 12-16 April 2021

New group members

Marie-Christine Zdora, Umut Sanli and Talgat Mamyrbayev officially join the X-ray Optics and Applications group as Post-Docs. We wish them every success!

Pazyryk carpet fibre

Insights into the world’s oldest pile carpet

High-resolution XRF imaging of the specific metal distribution within wool fibers at the PHOENIX beamline gives insights into traditional oriental dyeing procedures.

Grinenko et al

Split superconducting and time-reversal symmetry-breaking transitions in Sr2RuO4 under stress

Strontium ruthenate (Sr2RuO4) continues to present an important test of our understanding of unconventional superconductivity, because while its normal-state electronic structure is known with precision, its superconductivity remains unexplained. There is evidence that its order parameter is chiral, but reconciling this with recent observations of the spin part of the pairing requires an order parameter that is either finely tuned or implies a new form of pairing. Therefore, a definitive resolution of whether the superconductivity of Sr2RuO4 is chiral is important for the study of superconductivity.

 

Table of Content

Optimization of Nanofluidic Devices for Geometry-Induced Electrostatic Trapping

Single particle studies play an important role in understanding their physical and chemical properties. Electrostatic trapping is on one such robust method that allows for a contact-free high-throughput single nanoparticle trapping in an aqueous environment in a nanofluidic device. However, finding an optimum design solution for stiffer single particle trapping for different particles is a cumbersome process. This work presents all crucial geometrical parameters required to tune the trapping efficiency of the device, and their impact. Furthermore, the work enables to quickly identify and optimize nanofluidic devices design for stronger single particle confinement using numerical simulations, saving the massive experimental time required for device optimization.