Scientific Highlights
Mirror, mirror on the wall…
…. Now we know there are chiral phonons for sure
A compact gas attenuator for the SwissFEL ATHOS beamline realized using additive manufacturing
Gas attenuators are important devices providing accurate variation of photon intensity for soft X-ray beamlines. In the SwissFEL ATHOS beamline front-end the space is very limited and an innovative approach has been taken to provide attenuation of three orders of magnitude up to an energy of 1200 eV. Additive manufacturing of a differential pumping system vacuum manifold allowed a triple pumping stage to be realized in a space of less than half a meter. Measurements have shown that the response of the device is as expected from theoretical calculations.
Polymer electrolyte water electrolysis: Understanding the microstructure of a core-shell based anode catalyst layer
Reducing precious metal loading in the anodic catalyst layer (CL) is indispensable for lowering capital costs and enabling the widespread adoption of polymer electrolyte water electrolysis (PEWE). This work presents the first three-dimensional reconstruction of a TiO2-supported IrO2 based core shell catalyst layer, using high-resolution X-ray ptychographic tomography at cryogenic temperature of 90 K. The high data quality and phase sensitivity of the technique have allowed the reconstruction of all four phases namely pore space, IrO2, TiO2 support matrix and the ionomer network, the latter of which has proven to be a challenge in the past.
Dr Christian Wäckerlin is appointed as assistant professor at EPFL
Dr Christian Wäckerlin (*1983), currently Research and Teaching Associate at EPFL and Project Leader at the Paul Scherrer Institute (PSI), as Assistant Professor of Physics in the School of Basic Sciences. Christian Wäckerlin’s research focuses on nanoscience and quantum engineering.
A close look at temperature profiles during laser 3D printing
Operando X-ray diffraction was used to measure process zone temperatures in laser powder bed fusion and compared with finite element simulations.
X-rays look at nuclear fuel cladding with new detail
Micro-beam measurements at the Swiss Light Source SLS give insights into the crystal structure of hydrides that promote cracks in nuclear fuel cladding.
Laura Heyderman elected Royal Society Fellow
Laura’s nomination recognises almost 30 years of research into magnetic materials and magnetism on the nanoscale.
A deep look into hydration of cement
Researchers led by the University of Málaga show the Portland cement early age hydration with microscopic detail and high contrast between the components. This knowledge may contribute to more environmentally friendly manufacturing processes.
Apochromatic X-ray focusing
A team of scientists from the Paul Scherrer Institut, the University of Basel and DESY have demonstrated the first-ever realization of apochromatic X-ray focusing using a tailored combination of a refractive lens and a Fresnel zone plate. This innovative approach enables the correction of the chromatic aberration suffered by both refractive and diffractive lenses over a wide range of X-ray energies. This groundbreaking development in X-ray optics have been just published in the scientific journal Light: Science & Applications.
The evolution of O2 on Ir-based catalysts requires the complete oxidation of their surface to Ir+5
The evolution of O2 occurring in polymer electrolyte water electrolyzer anodes is a very slow reaction that must be catalyzed using iridium (Ir-) based materials. However, Ir is an extremely scarce metal, and thus the extended commercialization of these electrolyzers will only be possible if the amount of Ir implemented in their anodes is drastically reduced. This requires an improved understanding of the individual steps through which these Ir-based materials catalyze the evolution of O2. To shed light on this matter, in this work we studied four different Ir-based catalysts under operative conditions using time resolved X-ray absorption spectroscopy. Our results show for the first time that, despite the differences between these materials, their surfaces must systematically be completely oxidized to a +5 state in order for the evolution of O2 to proceed on them.