Researchers have established that a particularly stable form of WTe2 is a two-dimensional topological insulator, confirming recent predictions. The findings should provide new opportunities for fundamental studies of topological phenomena and for next-generation spintronic applications. ... Read more »
To celebrate DOE’s 40th anniversary (October 1, 2017), the Office of Science (SC) collected 40 scientific milestones from the previous 40 years, each one supported by SC. The ALS played a key role in two of the milestones: 2005 (ribosome) and 2009 (topological materials). ... Read more »
Photoemission electron microscopy (PEEM) experiments have demonstrated that the circulation direction of a magnetic vortex can be switched by the application of an electric field, opening the door to digital devices with more streamlined system designs, improved performance, and greater energy efficiency. ... Read more »
A powdery mix of metal nanocrystals wrapped in single-layer sheets of carbon atoms shows promise for safely storing hydrogen for use with fuel cells for passenger vehicles and other uses. Now, a new study provides insight into the atomic details of the crystals’ ultrathin coating and how it serves as selective shielding while enhancing their performance in hydrogen storage. ... Read more »
Copper oxides are important for superconductivity applications but are difficult to understand due to complex charge, spin, and orbital interactions. Now, studies at the ALS have found such a system in which observations of effective electron mass are at odds with state-of-the-art electronic-structure calculations. ... Read more »
Scientists are seeking ways to reduce levels of CO2 in the atmosphere by improving the processes that convert CO2 gas into ethanol (a liquid fuel). But copper, the best catalyst for this, is not very efficient. Now, ambient-pressure x-ray experiments have revealed how subsurface oxygen boosts copper’s catalytic activity.
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Three distinct crystalline phases with different electronic, magnetic, and optical properties were reversibly induced in a material through the insertion and extraction of ions by an electric field at room temperature. Such multifunctional materials are desirable for many applications, from smart windows to spintronics.
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Researchers have structurally and chemically “visualized” the surface of a silver–gold alloy as it reorganizes itself during catalytic activation. The insights gained from this methodology can lead to improved catalysts for energy-intensive industrial applications, thereby increasing efficiency and reducing waste.
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Working at the ALS, researchers have found another family of materials where they can both explore the physics of 2D topological insulators and do experiments that may lead to future applications. The material—known as 1T’-WTe2—bridges two flourishing fields of research: that of so-called 2D materials and topological materials. ... Read more »
Researchers have demonstrated a novel way to systematically strain-engineer oxygen vacancies in complex transition-metal oxide thin films. The work advances our ability to tailor such defects, small changes in which can lead to dramatic changes in material properties such as conductivity and magnetism. ... Read more »