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 »
Electrical Switching of Magnetic Vortex Circulation
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 »
New Study on Graphene-Wrapped Nanocrystals Makes Inroads Toward Next-Gen Fuel Cells
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 »
Elucidating the mechanism of MgB2 initial hydrogenation via a combined experimental–theoretical study
Magnesium borohydride Mg(BH4)2 is a promising solid-state hydrogen-storage material, releasing 14.9 wt% hydrogen upon conversion to MgB2. Although several dehydrogenation pathways have been proposed, the hydrogenation process is less well understood. This study elucidates the key atomistic mechanisms associated with the initial stages of hydrogen uptake within MgB2. Read more »
The Mystery of the Lightweight Electrons
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 »
Amorphous calcium carbonate particles form coral skeletons
Skeletons of Stylophora pistillata corals form by the attachment of amorphous calcium carbonate precursor particles, formed within the coral tissue, to the coral skeleton surface. This mechanism is faster than the precipitation of ions from solution and may render the corals less susceptible to ocean acidification than previously assumed. Read more »
Formation of a Photovoltaic Material from Precursor to Crystal
Lead halide perovskites have emerged as high-performance photovoltaic materials, demonstrating remarkably rapid improvements in efficiency. In situ printing and time-resolved x-ray characterization have provided new insights into the relationship between device efficiency, perovskite crystallinity, and film morphology. Read more »
Subsurface Oxygen Boosts Activity of Copper Catalysts
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. Read more »
A Bacterial Jigsaw Puzzle Is Solved
Bacterial microcompartments (BMCs) are hollow protein shells that encapsulate enzymes involved in bacterial metabolism. Crystallography studies have provided atomic-resolution views of a fully assembled BMC, revealing basic principles of shell construction for fighting pathogens or bioengineering applications. Read more »
Hybrid LED Phosphors Combine Performance and Durability
Light-emitting diodes (LEDs) last a long time and are very energy efficient. However, white LEDs currently rely on phosphor materials doped with rare-earth elements (REEs) that are increasingly costly and in short supply. A new class of hybrid phosphor materials shows promise as REE-free alternatives. Read more »
- « Previous Page
- 1
- …
- 61
- 62
- 63
- 64
- 65
- …
- 79
- Next Page »