This schematic of x-ray scattering is from a spiral antiferromagnet with a spin structure that gives rise to domains with jamming behavior. Using resonant magnetic x-ray photon correlation spectroscopy, this research shows that the domains of a spiral antiferromagnet enter a jammed state at the onset of long-range order. Researchers found that slow thermal fluctuations of the domain walls exhibit a compressed exponential relaxation with an exponent of 1.5 found in a wide variety of solid-like jammed systems and can be qualitatively explained in terms of stress release in a stressed network. As the temperature decreases, the energy barrier for fluctuations becomes large enough to arrest further domain wall fluctuations, and the domains freeze into a spatial configuration within 10 K of the Néel temperature. The relaxation times can be fitted with the Vogel-Fulcher law as observed in polymers, glasses, and colloids, thereby indicating that the dynamics of domain walls in an ordered antiferromagnet exhibit some of the universal features associated with jamming behavior. Read more »
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Protein-based assemblies with ordered nanometer-scale features in three dimensions are of interest as functional nanomaterials but are difficult to generate. Here we report that a truncated S-layer protein assembles into stable bilayers, which we characterized using cryogenic-electron microscopy, tomography, and X-ray spectroscopy. Read more »
In January 2013, the U.S. Food and Drug Administration approved NESINA for the treatment of type 2 diabetes in adults as an adjunct to diet and exercise. NESINA was invented by scientists at Takeda California, who used ALS Beamlines 5.0.2 and 5.0.3 to collect x-ray diffraction data.
Spin-coating is extensively used in the lab-based manufacturing of organic solar cells, including most of the record-setting cells. Aram Amassian and co-workers report in this study the first direct observation of photoactive layer formation as it occurs during spin-coating. The study provides new insight into mechanisms and kinetics of bulk heterojunction formation, which may be crucial for successful transfer to printing processes and scaling up production. Read more »
Gathering information on the evolution of small cracks in ceramic matrix composites used in hostile environments such as in gas turbines and hypersonic flights has been a challenge. It is now shown that sequences of microcrack damage in ceramic composites under load at temperatures up to 1,750 °C can be fully resolved with the use of in situ synchrotron x-ray computed microtomography. Read more »
HP Labs researchers have tackled a decades-old mystery relying on powerful ALS microscopy techniques—to better understand the fourth basic circuit element: the memristor. The memristor (short for “memory resistor”) joins the other passive elements—the capacitor, the resistor, and the inductor—to create a device with the ability to “remember” changes even when it loses power. Commercial development based on memristors offers the promise of computing systems with highly advanced energy efficiency and memory retention. Memristor-based memory could be a strong competitor for current flash memory.
Crystallographic Consulting has a varied client base that includes many of the participating research team (PRT) members at the Berkeley Center for Structural Biology (BCSB), which operates five ALS beamlines. Crystallographic Consulting also contracts beam time for another 10-12 companies. Most of their research supports pharmaceutical companies working on new treatments for metabolic diseases and cancer.
Alternatives to the current lithium-ion-based car batteries are at the forefront of the automotive industry’s research agenda—manufacturers want to build cars with longer battery life, and to do that they’re going to have to find new solutions. One promising battery material is magnesium (Mg)—it is more dense than lithium, it is safer, and the magnesium ion carries a two-electron charge, giving it potential as a more efficient energy source. Magnesium has a high volumetric capacity, which could mean more battery power in a smaller space. However, to bring Mg batteries to the commercial market, researchers must create new electrolytes with improved properties. The x-ray absorption spectroscopy (XAS) facilities at the ALS are vital to understanding the interfaces and active species in Mg batteries.
Understanding “whisker” growth—the spontaneous growth of long filament-like grains on the leads, or “legs,” of electronic components—is key to manufacturing reliable lead-free electrical and electronic equipment. Cisco Systems, one of the world’s largest networking equipment producers, has provided funding and technical support to a group of ALS users from Purdue University to research the mechanism and driving forces for whiskers, with the ultimate goal of defining effective mitigation measures.
With an increased demand for sustainable structures and efficient material use, the building industry is always looking for ways to extend their resources. Wood composites offer an opportunity to do this, saving building costs and in some cases increasing strength and durability. Researchers have used data gathered at the ALS to build a predictive computer simulation model that will provide insight into how certain wood species and adhesive types will interact. Technological advances are contributing to stronger, environmentally friendly composite materials that can be used in wood products such as furniture components or building materials.