Scientists use pressure to make liquid magnetism breakthrough

It sounds like a riddle: What do you get if you take two small diamonds, put a small magneticcrystal between them and squeeze them together very slowly?

The answer is a magnetic liquid, which seems counterintuitive. Liquids become solids under pressure, but not generally the other way around. But this unusual pivotal discovery, unveiled by a team of researchers working at the Advanced Photon Source (APS), a U.S. Department of Energy (DOE) Office of Science User Facility at DOE’s Argonne National Laboratory, may provide scientists with new insight into high-temperature superconductivity and quantum computing.

Though scientists and engineers have been making use of superconducting materials for decades, the exact process by which high-temperature superconductors conduct electricity without resistance remains a quantum mechanical mystery. The telltale signs of a superconductor are a loss of resistance and a loss of magnetism. High-temperature superconductors can operate at temperatures above those of liquid nitrogen (−320 degrees Fahrenheit), making them attractive for lossless transmission lines in power grids and other applications in the energy sector.

Read more on the APS website

Image: APS

Argonne scientists fashion new class of X-ray detector

The original Argonne press release by Jared Sagoff can be read here.

Getting an X-ray at the dentist or the doctor is at best a little inconvenient and at worst a little risky, as radiation exposure has been linked to an increased risk of cancer. But researchers may have discovered a new way to generate precise X-ray images with a lower amount of exposure, thanks to an exciting set of materials that is generating a lot of interest.

Scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory and Los Alamos National Laboratory have identified a new class of X-ray detectors based on layered perovskites, a semiconducting material also used in some other types of applications such as solar cells and light-emitting diodes. The detector with the new material is 100 times more sensitive than conventional, silicon-based X-ray detectors.

>Read more on the Advanced Photon Source website.

Image: Two-dimensional (2D) Ruddlesden-Popper phase layered perovskites (BA)2(MA)2Pb3I10 with three layers of inorganic octahedral slab and bulky organics as spacers.

Credit: Image by Dave Tsai/Los Alamos.

Crystals, lasers, glasses, and bent molecules: adventures in nonlinear optics

Light is an indispensable scientific tool. For example, laser-based optical sensors can detect oxygen in the environment, proteins in biomedical samples, and process markers in industrial settings, among other applications. However, not all wavelengths of light can be generated by a single laser, which limits what chemicals can be detected with optical sensing. That’s where nonlinear optical crystals can help. By shining multiple lasers with different wavelengths through such crystals, researchers can tune laser beams via frequency conversion and cover more of the optical spectra. This has been a successful approach for wavelengths from ultraviolet to near-infrared(IR), but the mid-IR region has lacked practical nonlinear optical crystals. However, crystals may not be the only game in town. A multi-institution international research team is exploring a possible solution to the crystal problem: cutting-edge glasses containing mercuric iodide. The idea is that these glasses could behave like nonlinear optical crystals, offering an enticing approach to the generation of novel amorphous optical materials. But first, the researchers needed to figure out what these glasses look like at the atomic scale. For that, they went to the U.S. Department of Energy’s (DOE’s) Advanced Photon Source (APS) to collect high-energy x-ray diffraction data. By combining the diffraction data with other structural data and computer modeling, the team uncovered the secrets behind how a glass can act like a crystal.

Nonlinear optical crystals are widely used in photonics applications, but can be challenging to synthesize. To sidestep the need for crystals, scientists have been pursuing glassy materials that can tune lasers. One challenge is that glassy materials with isotropic internal structures aren’t able to perform the frequency conversion necessary to tune lasers. However, glasses with chiral asymmetric properties have nonlinear optical potential. This research team is investigating hybrid molecular/network glasses with non-centrosymmetric mercuric iodide (HgI2).

>Read more on the Advanced Photon Source (APS) website

Image: Schematic representation of second harmonic generation as light passes through bent HgI2 molecules adopting a non-random orientation within mesoscopic domains of sulfide glass.

Researchers find what makes chocolate melt in your mouth

Scientists use X-rays to see the true nature of chocolate.

The taste of a silky piece of rich chocolate is one of life’s great pleasures, and producing a smooth mouthfeel is an aspiration of every serious chocolatier.  The characteristics that truly set haute chocolate apart can be seen at the microscale thanks to recent, pivotal research performed by researchers from the University of Guelph at the Advanced Photon Source (APS) located at the U.S. Department of Energy’s (DOE) Argonne National Laboratory.

In a series of studies, University of Guelph researcher Fernanda Peyronel used a technique called ultra-small-angle x-ray scattering (USAXS) to investigate a property called fractal dimension, a particular feature of the geometric configuration of tiny particles of chocolate. “Basically, we’re trying to see whether these particles have a more open or a more closed structure and to correlate that to the mouthfeel experienced by consumers,” Peyronel said.

The USAXS technique allows scientists to resolve particles that range in size from a few hundred nanometers to around 10 micrometers — roughly the limit at which our taste buds can distinguish different textures. The beamline at the APS also accommodates detectors for small-angle x-ray scattering as well as large-angle x-ray scattering. These allow scientists to study their systems from less than a nanometer to around 10 micrometers.

>Read more on the APS at Argonne website

The active role of collagen in building bones

We use our skeleton every day, but our mental model of our bones may look more like a glow-in-the-dark Halloween costume, or a teaching skeleton hanging on a sitcom set, than true anatomy. While these common representations of skeletons focus on the sturdy aspects of bones, the structural frames of actual bones are built by a soft organic portion. To create bones, the human body precipitates calcium phosphate minerals using collagen, a long protein, as scaffolding. Our bodies mineralize calcium phosphate both inside and outside collagen-confined spaces, and scientists are still working to understand how the two types of mineralization occur. Recent research at the U.S. Department of Energy’s Advanced Photon Source (APS) has investigated mineralization rates and shown that collagen structures reduce the energy barriers to mineralization by providing a substrate on which the calcium phosphate can precipitate. Since common bone diseases, such as osteoporosis, hinge on an abnormal calcium phosphate precipitation process, this improved understanding of the role of collagen in precipitation could lead to insight into the treatment of these diseases.

>Read more on the Advanced Photon Source at Argonne National Lab

Figure (extract, full image here) This scanning electron microscopy image shows calcium phosphate minerals nucleation in both extrafibrillar (purple colored image) and intrafibrillar (green colored image) spaces of collagen matrices. Without polyaspartic acid, extrafibrillar nucleation of calcium phosphate is dominant while with polyaspartic acid, intrafibrillar nucleation mainly occurs.

For superconductors, discovery comes from disorder

Discovered more than 100 years ago, superconductivity continues to captivate scientists who seek to develop components for highly efficient energy transmission, ultrafast electronics or quantum bits for next-generation computation.  However, determining what causes substances to become — or stop being — superconductors remains a central question in finding new candidates for this special class of materials.

In potential superconductors, there may be several ways electrons can arrange themselves. Some of these reinforce the superconducting effect, while others inhibit it. In a new study, scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have explained the ways in which two such arrangements compete with each other and ultimately affect the temperature at which a material becomes superconducting.

>Read more on the Advanced Photon Source at Argonne National Lab website

Image: This image shows the transition between Cooper pair density (indicated by blue dots) and charge density waves. Argonne scientists found that by introducing defects, they could disrupt charge density waves and increase superconductivity.
Credit:
Ellen Weiss / Argonne National Laboratory

Advanced Photon Source upgrade

The U.S. Department of Energy (DOE) Office of Science (SC) has given DOE’s Argonne National Laboratory approval in the next phase of the $815M upgrade of the Advanced Photon Source (APS), a premier national research facility that equips scientists for discoveries that impact our technologies, economy, and national security.
DOE’s Critical Decision 3 (CD-3) milestone approval is a significant recognition of DOE’s acceptance of Argonne’s final design report for the complex APS Upgrade (APS-U), and authorizes the laboratory to proceed with procurements needed to build the nation’s brightest energy, storage-ring based X-ray source. The upgrade positions the APS to be a global leader among the new generation of storage-ring light sources that is now emerging.
Argonne’s APS, which works like a giant X-ray microscope, is a DOE Office of Science User Facility supported by the Scientific User Facilities Division of the Basic Energy Sciences Program in the Office of Science. It produces extremely bright, focused X-rays that peer through dense materials and illuminate the structure and chemistry of matter at the molecular and atomic level. By way of comparison, the X-rays produced at today’s APS are up to one billion times brighter than the X-rays produced in a typical dentist office.

Read more on the APS at Argonne National Laboratory website

Research on shark vertebrae could improve bone disease treatment

The U.S. Department of Energy’s Advanced Photon Source (APS) at Argonne National Laboratory has facilitated tens of thousands of experiments across nearly every conceivable area of scientific research since it first saw light more than two decades ago.
But it wasn’t until earlier this year that the storied facility was used to study shark vertebrae in an experiment that one Northwestern University researcher hopes will shed light on the functionality of human bone and cartilage. Shark spines constantly flex when they swim, said Stuart R. Stock, a materials scientist and faculty member of Northwestern’s Feinberg School of Medicine. Yet they remain surprisingly resilient throughout the fish’s lifetime, he said.

Human bones, however, cannot endure the same kind of bending and become more fragile as people age. Stock is using the APS to better understand shark vertebrae’s formation and strength. He wants to know how the animal’s tissue develops and how it functions when the animal swims.

>Read more on the APS at Argonne National Laboratory website

Optical ​“tweezers” combine with X-rays to enable analysis of crystals in liquids

Understanding how chemical reactions happen on tiny crystals in liquid solutions is central to a variety of fields, including materials synthesis and heterogeneous catalysis, but obtaining such an understanding requires that scientists observe reactions as they occur.

By using coherent X-ray diffraction techniques, scientists can measure the exterior shape of and strain in nanocrystalline materials with a high degree of precision. However, carrying out such measurements requires precise control of the position and angles of the tiny crystal with respect to the incoming X-ray beam. Traditionally, this has meant adhering or gluing the crystal to a surface, which in turn strains the crystal, thus altering its structure and potentially affecting reactivity.

>Read more on the Advanced Photon Source at Argonne Laboratory website

Image: Scientists have found a way to use “optical tweezers” by employing lasers, a mirror and a light modulator to anchor a crystal in solution. The “tweezers” have made it possible to conduct X-ray diffraction measurements of a crystal suspended in solution.
Credit: Robert Horn/Argonne National Laboratory.

A new molecule could help put the STING on cancer

The protein STING (stimulator of interferon genes) is a component of the innate immune system. It plays a major role in the immune response to cancer, and abnormal STING signaling has been shown to be associated with certain cancers. Immunomodulatory approaches using agonists to target STING signaling are therefore being investigated as anticancer treatments. However, the compounds in clinical trials typically are injected intratumorally in patients with solid cancers. In this study, researchers discovered a novel STING agonist, known as an amidobenzimidazole (ABZI), which can be given by intravenous injection and could therefore potentially open up its evaluation as a treatment for hard-to-reach cancers. Using x-ray diffraction data collected at the U.S. Department of Energy’s Advanced Photon Source (APS), researchers from GlaxoSmithKline (GSK) investigated ABZI compounds and STING. Their results, published in the journal Nature, may have important implications for anticancer immunotherapy.

STING is a protein that mediates innate immunity, and one function of the STING signaling pathway is in mobilizing an immune response against tumors. STING proteins can be activated by cyclic dinucleotides, small molecules that are made by the cytosolic DNA sensor, cGAS, upon sensing of DNA leaking out of the nucleus as a result of DNA damage, including that which might be associated with cancer development.

>Read more on the Advanced Photon Source at Argonne National Lab.

Figure: X-ray crystal structure of the STING protein bound to one of the new molecules.

New technique for two-dimensional material analysis

Discovery allows scientists to look at how 2D materials move with ultrafast precision.

Using a never-before-seen technique, scientists have found a new way to use some of the world’s most powerful X-rays to uncover how atoms move in a single atomic sheet at ultrafast speeds.

The study, led by researchers at the U.S. Department of Energy’s (DOE) Argonne National Laboratory and in collaboration with other institutions, including the University of Washington and DOE’s SLAC National Accelerator Laboratory, developed a new technique called ultrafast surface X-ray scattering. This technique revealed the changing structure of an atomically thin two-dimensional crystal after it was excited with an optical laser pulse.
>Read more on the Advanced Photon Source at Argonne website
>Another article is also available on the Linac Coheren Light Source at SLAC website

Image: An experimental station at SLACs Linac Coherent Light Source X-ray free-electron laser, where scientists used a new tool they developed to watch atoms move within a single atomic sheet.
Credit: SLAC National Accelerator Laboratory

Unleashing perovskites’ potential for solar cells

Perovskites — a broad category of compounds that share a certain crystal structure — have attracted a great deal of attention as potential new solar-cell materials because of their low cost, flexibility, and relatively easy manufacturing process. But much remains unknown about the details of their structure and the effects of substituting different metals or other elements within the material. Now, researchers using the U.S. Department of Energy’s (DOE’s) Advanced Photon Source (APS) have been able to decipher a key aspect of the behavior of perovskites made with different formulations: With certain additives there is a kind of “sweet spot” where sufficient amounts will enhance performance and beyond which further amounts begin to degrade it. The findings were detailed in the journal Science.
Conventional solar cells made of silicon must be processed at temperatures above 1,400 degrees Celsius, using expensive equipment that limits their potential for production scale-up. In contrast, perovskites can be processed in a liquid solution at temperatures as low as 100 degrees, using inexpensive equipment. What’s more, perovskites can be deposited on a variety of substrates, including flexible plastics, enabling a variety of new uses that would be impossible with thicker, stiffer silicon wafers.

>Read more on the Advanced Photon Source (APS) website

Image: Perovskite-based solar cells are flexible, lightweight, can be produced cheaply, and could someday bring down the cost of solar energy. Shown here is the type of perovskite solar cell measured at the CNM/XSD Hard X-ray Nanoprobe at the APS.
Credit: Rob Felt

Illuminating a key industrial process

Results of research carried out at the U.S. Department of Energy’s (DOE’s) Advanced Photon Source (APS) may pave the way to improvements in industrial processes based on solvent extraction, which is used in the mining and refinement of technologically important rare earths. The results were published in the journal Physical Review Letters.
Rare earths such as lanthanides, which are elements in the range of atomic number 57 to 71, are not actually rare. They exist in large quantities in the world, but are only found in the form of trace amounts in rocks. Since rare earths are important for a variety of applications (e.g., electronics) their extraction is a major mining-related industry.
A common process by which rare earths are extracted involves dissolving rocks in acids, then shaking up the solution with an organic solvent and a surfactant. Under the right conditions, the desired ions move out of the aqueous phase and into the organic solvent.  This is known as “liquid-liquid extraction” or “solvent extraction,” and is conducted on a large scale by the mining industry. This process also separates heavier lanthanides from lighter lanthanides present in the same solution, because the heavier lanthanides separate more easily. While this fact is known and exploited in industrial separations processes, the nanoscale mechanisms of the separation process are not well understood.

>Read more on the Advanced Photon Source

Image: (a ) Schematic of system studied; positively charged lanthanide ions (blue circles) dissolve in the water, while the negatively charged surfactant molecules (purple) float on the water surface. (b) Data showing how density of ions at the surfactant surface jumps as the concentration of ions in the bulk water increases (Er=erbium, a heavier lanthanide, Nd=neodymium, a lighter lanthanide). The lines thru data are predictions from computer simulations. From M. Miller et al., Phys. Rev. Lett. 122, 058001 (2019).

The first observation of near-room-temperature superconductivity

For decades, room-temperature superconductivity has been one of physics’ ultimate goals, a Holy Grail-like objective that seems to keep drifting within realization yet always stubbornly out of reach. Various materials, theories, and techniques have been proposed and explored in search of this objective, but its realization has remained elusive. Yet recent experimental work on hydrogen-rich materials at high pressures is finally opening the pathway to practical superconductivity and its vast potential. Russell Hemley, a materials chemist at George Washington University in Washington, D.C., first announced evidence of superconductivity at 260 K in May, 2018, and then hints of an even higher 280 K transition in August of that year. Now Hemley, along with a team of researchers from The George Washington University and the Carnegie Institution for Science synthesized several lanthanum superhydride materials that demonstrated the first experimental evidence of superconductivity at near room temperature, and with colleagues from Argonne National Laboratory characterized them at the U.S. Department of Energy’s Advanced Photon Source (APS). Read more

Beam us up

The upgrade of the U.S. Department of Energy’s Advanced Photon Source at Argonne National Laboratory will make it between 100 and 1,000 times brighter than it is today.

That factor is such a big change, it’s going to revolutionize the types of science that we can do,” said Stephen Streiffer, Argonne Associate Laboratory Director for Photon Sciences and Director of the APS. We’ll be able to look at the structure of materials and chemical systems in the interior of things — inside a turbine blade or a catalytic reactor — almost down to the atomic scale. We haven’t been able to do that before. Given that vast change, we can only dream about the science we’re going to do.”
In December, DOE approved the technical scope, cost estimate and plan of work for an upgrade of APS.
The APS upgrade has been in the works since 2010. The upgrade will reveal a new machine that will allow its 5,500 annual users from university, industrial, and government laboratories to work at a higher spatial resolution, or to work faster with a brighter beam (a beam with more X-rays focused on a smaller spot) than they can now.

>Read more on the Advanced Photon Source at Argonne National Laboratory website

Image: A closeup of the magnets that will drive the upgraded APS beams.

Finding unusual performance in unconventional battery materials

Even as our electronic devices become ever more sophisticated and versatile, battery technology remains a stubborn bottleneck, preventing the full realization of promising applications such as electric vehicles and power-grid solar energy storage.  Among the limitations of current materials are poor ionic and electron transport qualities. While strategies exist to improve these properties, and hence reduce charging times and enhance storage capacity, they are often expensive, difficult to implement on a large scale, and of only limited effectiveness.  An alternative solution is the search for new materials with the desired atomic structures and characteristics.  This is the strategy of a group of researchers who, utilizing ultra-bright x-rays from the U.S. Department of Energy’s Advanced Photon Source (APS), identified and characterized two niobium tungsten oxide materials that demonstrate much faster charging rates and power output than conventional lithium electrodes.  Their work appeared in the journal Nature.

Currently, the usual approach for wringing extra capacity and performance from lithium-ion batteries involves the creation of electrode materials with nanoscale structures, which reduces the diffusion distances for lithium ions.  However, this also tends to increase the practical volume of the material and can introduce unwanted additional chemical reactions. Further, when graphite electrodes are pushed to achieve high charging rates, irregular dendrites of lithium can form and grow, leading to short circuits, overheating, and even fires.  Measures to prevent these dendrites generally cause a decrease in energy density.  These issues seriously limit the use of graphite electrodes for high-rate applications.

>Read more on the Advanced Photon Source website

Image: Artist’s impression of rapidly flowing lithium through the niobium tungsten oxide structure. This is a detail of the image, please see here for the entire art work.
Credit: Ella Maru Studio