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 »
A Multifunctional Material with Electric-Field Control
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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Fine-Tuning Oxygen Vacancies with Coherent Strain
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 »
A Seaweed Derivative Could Be Just What Lithium-Sulfur Batteries Need
Lithium-sulfur batteries have great potential as a low-cost, high-energy, energy source for both vehicle and grid applications. However, they suffer from significant capacity fading. Now, scientists have found that carrageenan, a seaweed derivative, acts as a stabilizer, allowing for more cycling and an extended lifetime. ... Read more »
Bacterial Symbiont Sequesters Arsenic and Barium in Sponges
Researchers used x-ray fluorescence, spectroscopy, and diffraction to study how populations of symbiotic bacteria can act as a detox organ in a host with no organs. The bacteria, members of the species Entotheonella, accumulate and mineralize large quantities of arsenic and barium in sponges. ... Read more »
Ptychography of a Bacterium’s Inner Compass
Magnetotactic bacteria (MTB) synthesize chains of magnetic nanocrystals (magnetosomes) that interact with the Earth’s magnetic field like an inner compass needle, simplifying their search for optimum environments. Ptychographic spectra of magnetosomes from a marine MTB provides insight into how these inner compasses form. ... Read more »
For Better Batteries, Open the Voltage Window
Electrochemical (battery) cells with aqueous electrolytes can be safe, inexpensive, and environmentally friendly, but they are limited by a narrow voltage window. X-ray absorption spectroscopy helps explain why an aqueous Na-ion system with Mn5O8 electrodes has a large voltage window and performs comparably to Li-ion batteries. ... Read more »
Magnetism Emerges at Wonky Interfaces
Researchers have found a new way to control magnetism at the atomic level that will serve as a model for studying emergent phenomena in other systems. The ability to engineer and tune properties on such small length scales can (eventually) enable us to design exciting new magnetic devices. ... Read more »
Exploring the Structure of Aqueous Solutions with SALSA
Researchers have published a series of papers that open up the possibility of probing hydrogen bonds in aqueous solutions by combining x-ray emission spectroscopy and resonant inelastic soft x-ray scattering, using the specialized Solid and Liquid Spectroscopic Analysis (SALSA) endstation at Beamline 8.0.1. ... Read more »
Scientists Trace ‘Poisoning’ in Chemical Reactions to the Atomic Scale
A team of researchers has employed a combination of measurements, including x-ray experiments at the ALS, to gather the most detailed information yet on problematic carbon-based deposits called “coke,” and to find ways to prevent its formation or reduce its effects. ... Read more »