Scientific Highlights
Spin-stripe phase in a frustrated zigzag spin-1/2 chain
Motifs of periodic modulations are encountered in a variety of natural systems, where at least two rival states are present. In strongly correlated electron systems, such behaviour has typically been associated with competition between short- and long-range interactions, for example, between exchange and dipole-dipole interactions in the case of ferromagnetic thin films.
Controllable Broadband Absorption in the Mixed Phase of Metamagnets
Combination of neutron scattering, muon spin relaxation, specific heat, ac and dc magnetization measurements, and electron magnetic resonance, reveals the ability of metamagnetic materials to absorb the electromagnetic radiation in an extremely broad frequency range.
Catalytically Active and Spectator Ce3+ in Ceria-Supported Metal Catalysts
Using time-resolved resonant X-ray emission spectroscopy, we quantitatively correlated the initial rate of Ce3+ formation under transient conditions to the overall rate of CO oxidation under steady-state conditions and showed that ceria reduction is a kinetically relevant step in CO oxidation, whereas a fraction of Ce3+ was present as spectators.
Catalytically Active and Spectator Ce3+ in Ceria-Supported Metal Catalysts
Identification of active species and the rate-determining reaction steps are crucial for optimizing the performance of oxygen-storage materials, which play an important role in catalysts lowering automotive emissions, as electrode materials for fuel cells, and as antioxidants in biomedicine. We demonstrated that active Ce3+ species in a ceria-supported platinum catalyst during CO oxidation are short-lived and therefore cannot be observed under steady-state conditions.
PSI-DESY Collaboration Delivers First Photonics Component for SwissFEL
The Photon Beam Intensity Gas (PBIG) monitor arrived at PSI at the end of May, and will be one of the first photonics components to be installed in the new SwissFEL facility.The gas-based photon beam position and intensity monitor is a device originally developed by Dr. Kai Tiedtke and his team at the Deutsches Elektronen-Synchrotron (DESY) for the non-destructive measurement of an X-ray FEL's beam position and flux. The accurate measurement of these variables is necessary due to the stochastic nature of the self-amplified spontaneous emission (SASE) process which can create jitters in the position and flux of the FEL beam on a shot-to-shot basis. The device has been developed and adapted to fit the SwissFEL parameters in a PSI-DESY collaboration over the course of two years.
Magnetoelectric domain control in multiferroic TbMnO3
The manipulation of domains by external fields in ferroic materials is of major interest for applications. In multiferroics with strongly coupled magnetic and electric order, however, the magnetoelectric coupling on the level of the domains is largely unexplored. We investigated the field-induced domain dynamics of TbMnO3 in the multiferroic ground state and across a first-order spin-flop transition.
Single- (K) and Double-Electron Excitation (KLII&III) XANES Spectra of α-Alumina and Aqueous Al3+•(H2O)6
X-ray absorption spectroscopy (XAS) probes the local environment around an atom by study of the local photoelectron’s scattering. Multielectron excitations become more important at higher x-ray dose, which are used for examples in x-FEL experiments. Here we demonstrate that multielectron excitations, observed in the Al K-edges EXAFS spectra can be used to derive structural information.
Metal organic frameworks for photo-catalytic water splitting
Growing experimental and computational evidence suggests that metal organic frameworks (MOFs) can make a meaningful contribution to catalytically promoted water splitting. They offer an impressive physical, spatial, chemical and electronic mutability with which to support and sustain water splitting half reactions. Their classical features à thermal stability, large surface area, high porosity and modularity à define them as versatile solid supports.
Beam Stoppers for SwissFEL
On the 5th of May the two beam stoppers were installed in the SwissFEL tunnel. These two blocks are made out of copper, recycled lead, steel and concrete blocks and weight 60 tons each. These stoppers are placed in front of both Aramis and Athos undulator lines.
Constraining interactions mediated by axion-like particles with ultracold neutrons
We report a new limit on a possible short range spin-dependent interaction from the precise measurement of the ratio of Larmor precession frequencies of stored ultracold neutrons and 199Hg atoms confined in the same volume. The measurement was performed in a ∼1μT vertical magnetic holding field with the apparatus searching for a permanent electric dipole moment of the neutron at the Paul Scherrer Institute.