Energy transition

Shifting away from nuclear energy, expanding solar and wind power, generating energy from biomass, reducing energy consumption. Switzerland is committed to becoming climate-neutral by 2050. An ambitious goal, which has become more urgent than ever due to the increasingly challenging geopolitical situation. How can a sustainable and resilient energy supply for Switzerland be established over the coming years? What's the optimal way to use renewable energy sources? What new technologies are especially promising? At PSI, researchers are seeking answers to these crucial questions.

Lehmann Nat Nanotech

Relation between microscopic interactions and macroscopic properties in ferroics

The driving force in materials to spontaneously form states with magnetic or electric order is of fundamental importance for basic research and device technology. The macroscopic properties and functionalities of these ferroics depend on the size, distribution and morphology of domains; that is, of regions across which such uniform order is maintained. Typically, extrinsic factors such as strain profiles, grain size or annealing procedures control the size and shape of the domains, whereas intrinsic parameters are often difficult to extract due to the complexity of a processed material. Here, we achieve this separation ...

 

Cover art of Small 16(33)

Phase contrast microtomography reveals nanoparticle accumulation in zebrafish

Metal-based nanoparticles are a promising tool in medicine – as a contrast agent, transporter of active substances, or to thermally kill tumor cells. Up to now, it has been hardly possible to study their distribution inside an organism. Researchers at the University of Basel in collaboration with the TOMCAT team have used phase contrast X-ray tomographic microscopy to take high-resolution captures of the nanoparticle aggregation inside zebrafish embryos.

The study was published in the journal Small and featured on the cover of its current issue.

Mahrt_Fabian

Welcome to Fabian Mahrt

We gladly announce that Fabian Mahrt has started to work as Postdoc in the Laboratory of Environmental Chemistry. He formally joined the Surface Chemistry group on 1 August 2020 but has started his work actually at the University of British Columbia (UBC), Canada.

cover_chem_sci_VUV

Methylbismuth: First observation of an organometallic biradical reactive intermediate

Open shell organometallic bismuth are promising agents for catalytic applications, but difficult to characterize due to their high reactivity. The simplest methylbismuth (Bi-CH3), a biradical species, was in-situ synthesized and spectroscopically characterized for the first time. Electronic and thermochemical properties could be obtained, which will guide future synthetic applications.

4 times compression factor for tomographic data feasible

In a recent study, TOMCAT has shown that lossy compression by a factor of at least 3 to 4 of raw acquisitions generally does not affect the reconstruction quality and that higher factors (six to eight times) can be achieved for tomographic volumes with a high signal-to-noise ratio as it is the case for phase-retrieved datasets. This finding is relevant to current challenges on large tomography data management and storage especially at synchrotron facilities. The results of this study was published in Journal of Synchrotron Radiation.

SandPedges

Study of Graphite Cycling in Sulfide Solid Electrolytes

Nowadays, most of the commercial Li-ion batteries employ graphite as the active material in negative electrodes. In the race for the next-generation Li-ion batteries, tremendous research efforts in academia and industry are carried out to replace the current flammable liquid electrolyte with a solid electrolyte, which could improve both, the batteries safety and energy density. Our study investigates two different sulfide-based solid electrolytes, 0.75Li2S-0.25P2S5 (LPS) and 0.3LiI-0.7(0.75Li2S-0.25P2S5), in combination with graphite and discloses the stability of the graphite-solid electrolyte interface. Optimizing the electrode morphology is the key to enhance the rate capability of all-solid-state cells. Using the special tender X-ray range allows chemical characterization of sulfur, phosphor and iodine.

microcalcs

Looking into the hints of early breast cancer detection

Microcalcifications are the most important indicator in the diagnosis of early breast cancer. The team of X-ray tomography group, in collaboration with Kantonsspital Baden, has carried out a reader study to characterize microcalcifications non-invasively using grating interferometry. This study reveals a potential way to discriminate benign and malignant lesions at early stage.

mu3e

Mu3e magnet arrived at PSI

After almost three years of planning, design and construction, the 31-ton, 2.6 Tesla superconducting magnet for the Mu3e experiment arrived today at PSI. The magnet delivery is an important milestone in the Mu3e experiment at the Laboratory of Particle Physics LTP, which will search for New Physics in muon decays over the next years.

 

The Mu3e Magnet arrived at PSI

We have received our solenoid magnet.

Integrated Circuits

The tiniest secrets of integrated circuits revealed

New research has demonstrated that the secrets of the tiniest active structures in integrated circuits can be revealed using a non-destructive imaging technique. The breakthrough required the efforts of an international team of scientists from JKU and Keysight Technologies (Austria), ETH/EPFL/PSI and IBM Research - Europe (Switzerland) and from UCL (UK).

Rosa et al

Colossal magnetoresistance in a nonsymmorphic antiferromagnetic insulator

Here we investigate antiferromagnetic Eu5In2Sb6, a nonsymmorphic Zintl phase. Our electrical transport data show that Eu5In2Sb6 is remarkably insulating and exhibits an exceptionally large negative magnetoresistance, which is consistent with the presence of magnetic polarons. From ab initio calculations, the paramagnetic state of Eu5In2Sb6 is a topologically nontrivial semimetal within the generalized gradient approximation (GGA), whereas an insulating state with trivial topological indices is obtained using a modified Becke−Johnson potential.

 

Flowchart

A tool to build and assess indices

Researchers from the Future Resilient Systems programme present a multiple criteria decision analysis (MCDA) software that supports the dynamic shaping and evaluation of indices.

3D rendering of an anti-tube

Miniaturized fluidic circuitry observed in 3D

The team of Prof. Thomas Hermans at the University of Strasbourg in France managed to create wall-less aqueous liquid channels called anti-tubes. Thanks to X-ray phase contrast tomography at the TOMCAT beamline those anti-tubes could be observed in 3D. The exciting results were published in Nature on May 6, 2020.

Montageraum 2020

Vorbereitung auf die praktische Prüfung

Neuer Montageübungsraum hat sich bewährt!

Zhang et al PRL

Many-Body Resonance in a Correlated Topological Kagome Antiferromagnet

We use scanning tunneling microscopy to elucidate the atomically resolved electronic structure in the strongly correlated kagome Weyl antiferromagnet Mn3Sn. In stark contrast to its broad single-particle electronic structure, we observe a pronounced resonance with a Fano line shape at the Fermi level resembling the many-body Kondo resonance. We find that this resonance does not arise from the step edges or atomic impurities but the intrinsic kagome lattice.

 

Feriencamp 2020

Feriencamp 2020

Am diesjährigen Feriencamp nahmen 36 Kinder von PSI-Mitarbeitenden teil und verbrachten eine interessante und tolle Woche am PSI. Herzlichen Dank allen Helfern, welche dieses Camp erst ermöglichen!

For the first time intrinsic resistivity of oxides directly measured at metal-oxide interface of irradiated Zr alloy claddings

Hydrogen uptake into Zr-based fuel claddings

At the hot surface of a fuel rod cladding in the reactor water, the water is partially dissociated in hydrogen and oxygen, leading to corrosion of the cladding and to the uptake of a part of the created hydrogen. Hydrogen in solid solution and in precipitated form changes the mechanical properties of the cladding tube. The uptake of the hydrogen through the dense oxide layer is unclear. The structure and physical properties of the oxide near the metal-interface is critical The resistivity of the oxide increases with distance from the interface. Nb-containing alloys show lower resistivity in the oxide close to the metal interface, and exhibit a lower hydrogen pick-up. The time in the reactor is an important factor, leading to increasing resistivity in the oxide close to the metal interface, and a higher hydrogen uptake late in life.

Relevance of the findings: considering resistivity, the model of hydrogen uptake is better understood, revealing hints for further cladding development.

Mainz testbeam July 2020

Beam test of the data acquisition in Mainz

Resuming beam operations, we have the opportunity to test a part of the data acquisiston sytem using the electron beam at the Mainz Microtron. We operate four pixel planes via two different front-end board prototypes to test the synchronization of across the system.

Sessi et al

Handedness-dependent quasiparticle interference in the two enantiomers of the topological chiral semimetal PdGa

It has recently been proposed that combining chirality with topological band theory results in a totally new class of fermions. Understanding how these unconventional quasiparticles propagate and interact remains largely unexplored so far. Here, we use scanning tunneling microscopy to visualize the electronic properties of the prototypical chiral topological semimetal PdGa.

 

Soter

Anna Sótér appointed Tenure Track Assistant Professor at ETH Zurich

Anna Sótér, currently Lecturer and SNSF Ambizione Fellow at ETH Zurich, formerly member of the PSI Laboratory for Particle Physics and member of the PSI Fellow program, has been appointed Tenure Track Assistant Professor of Low Energy Particle Physics. Anna Sótér’s research is in the area of exotic atoms, where particle physics, atomic physics and quantum optics meet.

Krieger et al

Proximity-Induced Odd-Frequency Superconductivity in a Topological Insulator

At an interface between a topological insulator (TI) and a conventional superconductor (SC), superconductivity has been predicted to change dramatically and exhibit novel correlations. In particular, the induced superconductivity by an s-wave SC in a TI can develop an order parameter with a p-wave component. Here we present experimental evidence for an unexpected proximity-induced novel super- conducting state in a thin layer of the prototypical TI, Bi2Se3 proximity coupled to Nb.

Chern Number

Cherned up to the maximum

In topological materials, electrons can display behaviour that is fundamentally different from that in ‘conventional’ matter, and the magnitude of many such ‘exotic’ phenomena is directly proportional to an entity known as the Chern number. New experiments establish for the first time that the theoretically predicted maximum Chern number can be reached — and controlled — in a real material.

Analytical Research Infrastructures of Europe (ARIEs)

Analytical Research Infrastructures as key resources for the five Horizon Europe Missions

Moon-shot missions, such as those of Horizon Europe, require exceptional solutions, and the world-leading Analytical Research Infrastructures of Europe (ARIEs) are one of the key places those solutions can be sought. The ARIE Joint Position Paper highlighting how the common, complementary approach will help address the societal challenges of the Horizon Europe Missions framework programme was presented today.