Scientific Highlights
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.
The Swiss Battery Days 2020/2021
A world without batteries? Unimaginable! They transform our electronic devices into wireless and portable objects.
Strong Superexchange in a d^(9−δ) Nickelate Revealed by Resonant Inelastic X-Ray Scattering
The discovery of superconductivity in a d9−δ nickelate has inspired disparate theoretical perspectives regarding the essential physics of this class of materials. A key issue is the magnitude of the magnetic superexchange, which relates to whether cuprate-like high-temperature nickelate superconductivity could be realized. We address this question using Ni L-edge and O K-edge spectroscopy of the reduced d9−1/3 trilayer nickelates R4Ni3O8 (where R = La, Pr) and associated theoretical modeling.
Temperature Dependent Water Transport Mechanism
Subsecond and submicron operando X-ray tomographic microscopy (XTM) was applied to reveal the water dynamics inside the gas diffusion layer (GDL) of polymer electrolyte fuel cells (PEFC). Utilizing the instrumental advancements in operando XTM of PEFCs the contribution of capillary-fingering and phase-change-induced flow on water transport in GDLs was quantified, for the first time during fuel cell startup at different operation temperatures.
Sustainable Synthesis of Bimetallic Single Atom Gold-Based Catalysts with Enhanced Durability in Acetylene Hydrochlorination
Platinum chloride in aqueous solution promotes the dispersion of large gold nanoparticles (>70 nm) on carbon carriers into single atoms, forming bimetallic single-atom catalysts with improved resistance against sintering at temperatures up to 800 K and under the harsh reductive reaction conditions of acetylene hydrochlorination, leading to improved lifetime in this reaction. To rationalize these observations, this study, led by ETH Zurich, utilized X-ray adsorption spectroscopy conducted at the SuperXAS beamline of the SLS to provide insights into the degree of gold dispersion and the structure of the isolated metal sites in the bimetallic catalysts.
Decomposing Magnetic Dark-Field Contrast in Spin Analyzed Talbot-Lau Interferometry: A Stern-Gerlach Experiment without Spatial Beam Splitting
We have recently shown how a polarized beam in Talbot-Lau interferometric imaging can be used to analyze strong magnetic fields through the spin dependent differential phase effect at field gradients. While in that case an adiabatic spin coupling with the sample field is required, here we investigate a nonadiabatic coupling causing a spatial splitting of the neutron spin states with respect to the external magnetic field. This subsequently leads to no phase contrast signal but a loss of interferometer visibility referred to as dark-field contrast.
Structural involvement in the melting of the charge density wave in 1T-TiSe2
The authors find using resonant and non-resonant x-ray diffraction on an x-ray free electron laser that the structural distortion and the underlying electronic structure of the charge density wave in TiSe2 show different energetics at ultrafast timescales. This indicates that the lattice distortion stabilizes the charge density wave.
Ultrafast calorimetry of deeply supercooled water
FEL-based ultrafast calorimetry measurements show enhancement and maximum in the isobaric specific-heat.
Cutting the cost of splitting water
Hydrogen can be extracted from water and stored as fuel. But the world needs better catalysts to make this process sustainable and affordable.
Muon rakers bring particles into line
Muons can be created through collisions between protons and nuclei, but need to be controlled in order to be useful.