Understanding the early stages of interactions between oxygen and material surfaces is beneficial for fields ranging from materials degradation to forensics and catalysis. In situ atom probe tomography (APT) is demonstrated to track the diffusion of oxygen and metal ions at nanoscale spatial resolution during the early stages of oxidation of a model Fe–Cr–Ni alloy. Read more »
ALS Work Using XANES
X-ray absorption near-edge structure (XANES) spectroscopy is form of x-ray absorption spectroscopy (XAS) that reveals the structures of molecules bonded to surfaces. It focuses on prominent features in the "near-edge" region of a spectrum (about 30 eV above the K-shell absorption edge). This "fine structure" can be correlated with specific molecular bond types, lengths, and orientations. XANES, also known as near-edge x-ray absorption fine-structure (NEXAFS) spectroscopy, is often performed as part of a STXM experiment.
New Insight into Titan’s Hazy Atmospheric Chemistry
Researchers simulated the complex chemistry that may be occurring in the hazy atmosphere of Saturn’s largest moon, Titan, and analyzed the reaction products at the ALS. The work provided new insights into what future Titan probes may encounter upon arrival and what the atmosphere of Earth may have been like eons ago. Read more »
Decoupling the metal–insulator transition temperature and hysteresis of VO2 using Ge alloying and oxygen vacancies
The VO2 metal–insulator transition underpins applications in thermochromics, neuromorphic computing, and infrared vision. Ge alloying is shown to expand the stability of the monoclinic phase to higher temperatures, and by suppressing the propensity for oxygen vacancy formation, renders the hysteresis of the transition exquisitely sensitive to oxygen stoichiometry. Read more »
Removing Nitrogen from Wastewater using Horizontal Levees
Treated municipal wastewater often contains nitrogen, which has been linked to algal blooms that can devastate coastal ecosystems. In a recent study, researchers characterized the primary nitrogen-removal pathways in a horizontal levee, an engineered subsurface water-treatment system consisting of a gently sloping strip of land adjacent to storm-control levees. Read more »
Additive Lithography–Organic Monolayer Patterning Coupled with an Area-Selective Deposition
This scene depicts the layer-by-layer growth of an inorganic film in a selected area. The alternation of a chemical agent (blue) deposits on a gray substrate to form an inorganic film. A cross-linked organic material (tan) locally inhibits this reaction and prevents film deposition. Furthermore, the pattern-wise cross-linking of this organic film enables nanoscale pattern generation. Read more »
Molecular Complex Removes Copper Ions from Water
X-ray analyses provided key insights into the copper uptake mechanisms in a new organic-inorganic hybrid material that quickly and selectively removes copper ions from water. The material provides an efficient tool for copper remediation as well as a blueprint for creating other hybrid materials for removing toxic metals from water. Read more »
Survival of T. rex Microvascular Structures from Deep Time
Researchers used several analytical techniques at the ALS to demonstrate how soft-tissue structures may be preserved in dinosaur bones, countering long-standing scientific dogma that protein-based body parts cannot survive more than one million years. Read more »
Berkeley Lab Helps Reveal How Dinosaur Blood Vessels Can Preserve Through the Ages
A team of scientists used infrared and x-ray imaging performed at the Advanced Light Source to determine the chemical mechanisms that allow soft tissue structures to persist in dinosaur bones—countering the long-standing scientific dogma that protein-based body parts can’t survive more than 1 million years. Read more »
ALS Confirms Mechanism for Improved Fuel Cell Catalysis
Aided by x-ray absorption spectroscopy at the ALS, researchers from Toyota and the University of Akron have uncovered a new catalysis mechanism to improve oxidation-reduction reactions in certain fuel cells by 40%. This enhancement, based on tin oxide, will support efforts to increase fuel efficiency in electric vehicles. Read more »
Clues to the Early Solar System Preserved in a Meteorite
Scientists analyzing a tiny carbon-rich pocket inside a meteorite found unexpected chemical signatures. Their findings are the first direct evidence that material from the outer solar system may have traveled inward long before planets formed, providing insight into the early solar system. Read more »
