Scientific Highlights
Time- and spatially-resolved magnetization dynamics driven by spin-orbit torques
Current-induced spin-orbit torques hold a great potential for manipulation of magnetization at ultrafast timescales. Researchers at ETH Zürich have demonstrated, using time-resolved STXM imaging at the Swiss Light Source, the influence of spin-orbit torques on the switching behaviour of Pt/Co/AlOx nanostructured elements.
Making the world go round - a look into the structure of a prominent heterogeneous catalyst
Fluid catalytic cracking catalysts, which are composite particles of hierarchical porosity, were examined using ptychographic X-ray tomography. These particles are essential to the conversion of crude oil into gasoline. Examination of catalysts at decreasing levels of catalytic conversion efficacy allowed the detection of possible deactivation causes.
Coulomb spin liquid in anion-disordered pyrochlore Tb2Hf2O7
The charge ordered structure of ions and vacancies characterizing rare-earth pyrochlore oxides serves as a model for the study of geometrically frustrated magnetism. The organization of magnetic ions into networks of corner-sharing tetrahedra gives rise to highly correlated magnetic phases with strong fluctuations, including spin liquids and spin ices. It is an open question how these ground states governed by local rules are affected by disorder.
Frustratingly disordered
A study of how disorder affects a ‘frustrated’ magnet reveals a surprising robustness of the underlying quantum many-body state, and provides evidence for emerging quantum phenomena induced by disorder.
Highly Crystalline C8-BTBT Thin-Film Transistors by Lateral Homo-Epitaxial Growth on Printed Templates
Highly crystalline thin films of organic semiconductors offer great potential for high-performance, low-cost flexible electronics. Researchers at IMEC Belgium have developed a new double-step thin film fabrication process that offers higher performance devices. Soft X-ray spectro-microscopy at the Swiss Light Source was used to prove that the increased performance comes from larger areas of material sharing the same molecular orientation.
Johannes Ihli and co-researchers made it into Nature Communications
Nature Communications will be publishing the paper of Johannes Ihli et al., "A three-dimensional view of structural changes caused by deactivation of fluid catalytic cracking catalysts", in issue 8, article number 809. The paper has already gone online on October 9, 2017.
Tracking the Chemical Transformations at a Zeolite Brønsted Acid Site with Al K-edge XANES
Al T-sites are of crucial importance for the function of zeolite catalysts. These T-sites, which serve as Brønsted acid reaction centers, interact strongly with water. The location of these T-sites and their chemical state in the presence of water were elucidated using x-ray absorption spectroscopy (XAS) at the PHOENIX beamline at the Swiss Light Source of the PSI.
Pt nanoparticles: The key to improved stress corrosion cracking mitigation in boiling water reactors
The formation and growth of cracks by stress corrosion cracking (SCC)in reactor internals and recirculation pipes due to the highly oxidising environment is a serious issue in boiling water reactors. At first, SCC mitigation was attempted by injecting H2 into the feed water, where the injected H2 recombines with the H2O2 and O2 to water and reduces the electrochemical corrosion potential, and consequently the SCC susceptibility. Several disadvantages of the injection of high amounts of H2, have led to the development of noble metal additions to the reactor feed water. With injection of a much smaller amount of H2, the noble metal particles of a few nanometres in size, formed in-situ, work as catalysts for the efficient reduction of the oxidizing species formed by radiolysis, and thus lower the ECP and SCC susceptibility.
Best publication
A team of GFA and CPT physicists has worked out a novel achromatic beam optics concept for a proton therapy gantry. The article on the concept in the journal Zeitschrift für Medizinische Physik has been awarded a prize for the best publication in 2016. The jury states: „The paper of Alexander Gerbershagen et al. entitled „A novel beam optics concept in a particle therapy gantry utilizing the advantages of superconducting magnets” describes a new concept of a first order design of the beam optics of a superconducting proton therapy gantry beam. The jury was impressed by the well-structured experimental work with clear improvement of large momentum acceptance in the gantry which opens the possibility of implementation new and faster dose application techniques in proton therapy.”
Light from the particle accelerator helps to understand ozone decomposition
PSI researchers have developed an experimental chamber in which they can recreate atmospheric processes and probe them with unprecedented precision, using X-ray light from the Swiss Light Source SLS. In the initial experiments, they have studied the production of bromine, which plays an essential role in the decomposition of ozone in the lower layers of the atmosphere. In the future, the new experiment chamber will also be available for use by researchers from other scientific fields.