Scientific Highlights
Towards understanding of human betacoronavirus HKU1 life cycle
Researchers from China and USA join forces with Swiss Light Source (SLS) macromolecular crystallography (MX) beamline scientists in a study, which aims at understanding an important step in the life cycle of the human betacoronavirus HKU1.
3-D X-ray imaging makes the finest details of a computer chip visible
Researchers at the PSI have made detailed 3-D X-ray images of a commercially available computer chip. In their experiment, they examined a small piece that they had cut out of the chip beforehand. This sample remained undamaged throughout the measurement. It is a major challenge for manufacturers to determine if, in the end, the structure of their chips conforms to the specifications. Thus these results represent one important application of an X-ray tomography method that the PSI researchers have been developing for several years.
Interlaced zone plates push the resolution limit in x-ray microscopy
A novel type of diffractive lenses based on interlaced structures enable x-ray imaging at resolutions below 10 nm. The fabrication method and the test results of these novel x-ray lenses have been published in the journal Scientific Reports.
Nanotechnology enables new insights into chemical reactions
Eighty percent of all products of the chemical industry are manufactured with catalytic processes. Catalysis is also indispensable in energy conversion and treatment of exhaust gases. Industry is always testing new substances and arrangements that could lead to new and better catalytic processes. Researchers of the Paul Scherrer Institute PSI in Villigen and ETH Zurich have now developed a method for improving the precision of such experiments, which may speed up the search for optimal solutions.
The Smallest Magnet
Single holmium atoms adsorbed on few monolayers of magnesium oxide are extraordinarily stable magnets. They retain a significant fraction of their magnetization when the external magnetic field is switched off. This has been shown recently in a study combining x-ray magnetic circular dichroism performed at the Swiss Light Source (SLS) and at the European Synchrotron Radiation Facility (ESRF) as well as scanning tunneling microscopy. The results open perspectives of storing and processing information at ultrahigh density.
Novel insulating phase in iron-pnictide materials
The first example of an insulating phase which is close to the superconducting phase in an iron-pnictide system has been recently observed in heavy Cu-doped NaFe1-xCuxAs (x > 0.3). A combined study by angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT) calculations revealed that on-site Coulomb repulsion and enhanced Hund’s rule coupling are responsible for the insulating behavior. The results show that the insulating phase in NaFe0.5Cu0.5As resembles the situation in the parent compounds of the high-Tc cuprate superconductors.
Selectively conductive or insulating
The material neodymium nickel oxide is either a metal or an insulator, depending on its temperature. The possibility to control this transition electrically makes the material a potential candidate for transistors in modern electronic devices. By means of a sophisticated development of X-ray scattering, researchers at the Paul Scherrer Institute PSI have now been able to track down the cause of this transition: electrons around the oxygen atoms are rearranging.
Magnesium Oxide Boosts the Hysteresis of Single-Molecule Magnets
Researchers from PSI and EPFL have demonstrated that the magnetization hysteresis and remanence of TbPc2 single-molecule magnets drastically depends on the substrate on which they are deposited. If a few atomic layers thick magnesium oxide film grown on a silver substrate is used, a record wide hysteresis and record large remanence can be obtained. Single-molecule magnets are attractive for molecular spintronics applications such as information processing or storage.
Shedding light on the origins of high-Tc superconductivity in bismuth oxides
Researchers have overcome a number of challenges in order to employ an advanced probe in the study of an unusual material, barium bismuth oxide (BaBiO3) – an insulating parent compound of a family of high-temperature superconductors known since the late 80s. In order to finally realize the experiments, the researchers grew and studied thin films of the material completely in situ under ultrahigh vacuum conditions. The results show that superconductivity in bismuth oxides emerges out of a novel insulating phase, where hole pairs located on combinations of the oxygen orbitals are coupled with distortions of the crystal lattice.