Scientists find ordered magnetic patterns in disordered magnetic material

Study led by Berkeley Lab scientists relies on high-resolution microscopy techniques to confirm nanoscale magnetic features.

A team of scientists working at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) has confirmed a special property known as “chirality” – which potentially could be exploited to transmit and store data in a new way – in nanometers-thick samples of multilayer materials that have a disordered structure.

While most electronic devices rely on the flow of electrons’ charge, the scientific community is feverishly searching for new ways to revolutionize electronics by designing materials and methods to control other inherent electron traits, such as their orbits around atoms and their spin, which can be thought of as a compass needle tuned to face in different directions.

These properties, scientists hope, can enable faster, smaller, and more reliable data storage by facilitating spintronics – one facet of which is the use of spin current to manipulate domains and domain walls. Spintronics-driven devices could generate less heat and require less power than conventional devices.

In the latest study, detailed in the May 23 online edition of the journal Advanced Materials, scientists working at Berkeley Lab’s Molecular Foundry and Advanced Light Source (ALS) confirmed a chirality, or handedness, in the transition regions – called domain walls – between neighboring magnetic domains that have opposite spins.

Scientists hope to control chirality – analogous to right-handedness or left-handedness – to control magnetic domains and convey zeros and ones as in conventional computer memory.

>Read more on the Advanced Light Source website

Image: (extract, here original image)The top row shows electron phase, the second row shows magnetic induction, and the bottom row shows schematics for the simulated phase of different magnetic domain features in multilayer material samples. The first column is for a symmetric thin-film material and the second column is for an asymmetric thin film containing gadolinium and cobalt. The scale bars are 200 nanometers (billionths of a meter). The dashed lines indicate domain walls and the arrows indicate the chirality or “handedness.” The underlying images in the top two rows were producing using a technique at Berkeley Lab’s Molecular Foundry known as Lorentz microscopy.
Credit: Berkeley Lab

New director of Berkeley Lab’s Advanced Light Source

After an international search, Stephen D. “Steve” Kevan has been named the new director of the Advanced Light Source (ALS) at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab).

The ALS produces extremely bright X-ray, infrared, and extreme ultraviolet light for more than 2,000 visiting scientists each year. Up to 40 experiments can be performed simultaneously using the synchrotron, resulting in nearly 1,000 peer-reviewed scientific articles each year across a range of fields, from chemistry and materials sciences to biology and environmental sciences. The facility draws on the Lab’s unique and long-standing expertise in designing, building, and operating world-class accelerators to advance scientific research.

Kevan, a condensed matter physicist, has served as ALS director in an interim capacity since January, when the preceding director, Roger Falcone, stepped down after more than 11 years in the role. Previously, Kevan was the ALS division deputy for science for more than five years and has been on the faculty of the University of Oregon’s physics department since 1986.

Kevan takes on the role of ALS director at a pivotal point in its history. The facility, which will celebrate its 25th anniversary later this year, is taking its first steps toward a major upgrade, dubbed “ALS-U.”

>Read more on the Advanced Light Source website

Image: Steve Kevan

Real-time ptychographic data streaming

CAMERA/ALS/STROBE Collaboration yields novel image data workflow pipeline.

What began nearly a decade ago as a Berkeley Lab Laboratory-Directed Research and Development (LDRD) proposal is now a reality, and it is already changing the way scientists run experiments at the Advanced Light Source (ALS)—and, eventually, other light sources across the Department of Energy (DOE) complex—by enabling real-time streaming of ptychographic image data in a production environment.

In scientific experiments, ptychographic imaging combines scanning microscopy with diffraction measurements to characterize the structure and properties of matter and materials. While the method has been around for some 50 years, broad utilization has been hampered by the fact that the experimental process was slow and the computational processing of the data to produce a reconstructed image was expensive. But in recent years advances in detectors and x-ray microscopes at light sources such as the ALS have made it possible to measure a ptychographic dataset in seconds.

>Read more on the Berkeley Lab website

Picture: The modular, scalable Nanosurveyor II system—now up and running at the ALS—employs a two-sided infrastructure that integrates the ptychographic image data acquisition, preprocessing, transmission and visualization processes.

ALS passes the 7000-protein milestone

The eight structural biology beamlines at the ALS have now collectively deposited over 7000 proteins into the Protein Data Bank (PDB), a worldwide, open-access repository of protein structures. The 7000th ALS protein structure (entry no. 6C7C) is an enzyme from Mycobacterium ulcerans (strain Agy99), solved with data from Beamline 5.0.2. This bacterium produces a toxin that eats away at skin tissue, causing what’s known as Buruli ulcers (Google at your own risk!). The bacterium is antibiotic-resistant, and treatment involves the surgical removal of infected tissues, including amputation.

The enzyme structure was solved by a group from the Seattle Structural Genomics Center for Infectious Disease (SSGID), whose mission is to obtain crystal structures of potential drug targets on the priority pathogen list of the National Institute of Allergy and Infectious Diseases (NIAID). As of May 2018, SSGCID has deposited 1090 structures in the PDB, with data for more than a quarter of those collected at ALS beamlines.

>Read more on the Advanced Light Source website

Image: PDB 6C7C: Enoyl-CoA hydratase, an enzyme from M. ulcerans (strain Agy99).

Rational optimization of organic solar-cell materials

Respiratory virus study points to likely vaccine target

Monovalent Manganese for High-Performance Batteries

The discovery enables the design of a high-performance, low-cost battery that, according to its developers, outperforms Department of Energy goals on cost and cycle life for grid-scale energy storage.

The widespread deployment of renewable energy sources such as solar and wind power destabilizes the electric grid because conventional power-generation systems cannot ramp quickly enough to balance the power variations from these intermittent sources. Storing energy in batteries could help to even things out, but the cost of most existing technologies—including lithium-ion batteries—is significant, hindering grid-scale applications.

Emerging storage technologies such as aqueous sodium (Na) systems offer low costs for long-duration storage, but they do not have the charge/discharge rates needed to balance volatile power generation. In particular, it remains a critical challenge to develop a stable negative electrode (anode) for high-rate Na-ion battery systems.

A battery breakthrough

Compared with the relatively mature designs of anodes used in Li-ion batteries, anodes for Na-ion batteries remain an active focus of research and development. Natron Energy (formerly Alveo Energy), a battery-technology company based in Santa Clara, California, developed an unconventional anode design using a blend of elements chemically similar to the paint pigment known as Prussian blue.

>Read more on the Advanced Light Source website

Image: Atomic structure of an electrode material, manganese hexacyanomanganate (MnHCMn), that achieved high performance in a sodium-ion battery. The open framework contains large interstices and channels that allow sodium (Na) ions to move in and out with near-zero strain. Manganese (Mn) ions form the corners of the cage: Mn(N) has six nitrogen nearest neighbors and Mn(C) has six carbon nearest neighbors.

Toward control of spin states for molecular electronics

Scientists develop sugar-coated nanosheets to target pathogens

Molecular Foundry-designed 2-D sheets mimic the surface of cells

Researchers have developed a process for creating ultrathin, self-assembling sheets of synthetic materials that can function like designer flypaper in selectively binding with viruses, bacteria, and other pathogens.
In this way the new platform, developed by a team led by scientists at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), could potentially be used to inactivate or detect pathogens.

The team, which also included researchers from New York University, created the synthesized nanosheets at Berkeley Lab’s Molecular Foundry, a nanoscale science center, out of self-assembling, bio-inspired polymers known as peptoids. The study was published earlier this month in the journal ACS Nano.
The sheets were designed to present simple sugars in a patterned way along their surfaces, and these sugars, in turn, were demonstrated to selectively bind with several proteins, including one associated with the Shiga toxin, which causes dysentery. Because the outside of our cells are flat and covered with sugars, these 2-D nanosheets can effectively mimic cell surfaces.

>Read more on the Advanced Light Source website

Image: A molecular model of a peptoid nanosheet shows loop structures in sugars (orange) that bind to the Shiga toxin (shown as a five-color bound structure at upper right).
Credit: Berkeley Lab

Secretary of Energy visits Berkeley Lab

Secretary of Energy Rick Perry visited Berkeley Lab on March 27, stopping at the Advanced Light Source, Molecular Foundry, NERSC, and ESnet.

Secretary of Energy Rick Perry visited the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) today, getting a firsthand view of how Berkeley Lab combines team science with world-class facilities to develop solutions for the scientific, energy, and technological challenges facing the nation.

As the top official at the Department of Energy, Perry oversees Berkeley Lab and the 16 other DOE national laboratories that form the backbone of the nation’s scientific infrastructure.

His visit began with a welcome and brief introduction to Berkeley Lab, followed by tours of several of the Lab’s DOE Office of Science user facilities, which provide state-of-the-art resources for scientists across the nation and around the world. After the tour, Perry addressed the Berkeley Lab community in a town hall meeting that was livestreamed to Lab staff.

“One of the things that I enjoy as much about this job as anything, is going and telling the uninitiated about what’s happening at the national labs in this country. Your engagement in the future of the sciences, in innovation and knowledge, is invaluable,” said Secretary Perry at the town hall.

> Read more on the Berkeley Lab website
>Discover more about the Advanced Light Source in Berkeley

Image: The Advanced Light Source, synchrotron facility the Secretary of Energy Rick Perry visited on March 274th 2018.

Phase diagram leads the way to tailored metamaterial responses

COSMIC impact: next-gen X-ray microscopy platform now operational

A next-generation X-ray beamline now operating at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) brings together a unique set of capabilities to measure the properties of materials at the nanoscale.

Called COSMIC, for Coherent Scattering and Microscopy, this X-ray beamline at Berkeley Lab’s Berkeley Lab’s Advanced Light Source (ALS) allows scientists to probe working batteries and other active chemical reactions, and to reveal new details about magnetism and correlated electronic materials.
COSMIC has two branches that focus on different types of X-ray experiments: one for X-ray imaging experiments and one for scattering experiments. In both cases, X-rays interact with a sample and are measured in a way that provides, structural, chemical, electronic, or magnetic information about samples.

The beamline is also intended as an important technological bridge toward the planned ALS upgrade, dubbed ALS-U, that would maximize its capabilities.

>Read more on the Advanced Light Source website

Image: X-rays strike a scintillator material at the COSMIC beamline, causing it to glow.
Credit: Simon Morton/Berkeley Lab

Tuning the electronic structure of a 2D material

Stacked 2D materials possess an array of tunable properties that are expected to be important for future applications in electronics and optics.

When some atomically thin—or 2D—materials are stacked like Lego bricks in different combinations with other ultrathin materials, new properties often emerge that are potentially useful for next-generation device applications. For example, tungsten disulfide (WS2) is a semiconductor that belongs to a family of 2D materials (transition-metal dichalcogenides, or TMDs) that have received an enormous amount of interest due to their many advantageous properties that can be tuned by mixing and matching them in stacks with other 2D materials.

In this work, single-layer WS2 was stacked on a thin flake of hexagonal boron nitride (h-BN), all on a base of titanium dioxide (TiO2). This heterostructure provided a stable, non-interacting platform that enabled a team of researchers to directly and accurately probe the WS2 electronic states and excitations, including the effects of interactions between the electrons themselves (many-body effects), at a level of detail not previously possible.

MAESTRO’s exquisite sensitivity

MAESTRO (Microscopic and Electronic Structure Observatory), a facility at ALS Beamline 7.0.2 that opened to scientists in 2016, can handle very small sample sizes, on the order of tens of microns, which is key to studying 2D materials. Scientists are continuing to push MAESTRO’s capabilities to study even smaller features—down to the nanoscale. The endstation also features the ability to fabricate and manipulate samples for x-ray studies while maintaining pristine conditions that protect them from contamination.

>Read more on the Advanced Light Source website

Image: Rendering of the atomic structure of a 2D layer of tungsten disulfide, or WS2 (blue and yellow), on top of layers of 2D boron nitride (silver and gold). Above that is a representation of the WS2 conduction band (pink-edged metallic surface) and valence bands (green- and blue-edged metallic surfaces). The results of this experiment suggest that the observed increase in valence-band splitting could be due to the presence of “trions,” exotic three-particle combinations of holes and electrons (red circles), in the conduction and valence bands. The background shows the raw WS2 electronic-structure data, as measured in the experiment.
Credit: Chris Jozwiak/Berkeley Lab

Study suggests water may exist in Earth’s lower mantle

Water on Earth runs deep – very deep. The oceans have been measured to a maximum depth of 7 miles, though water is known to exist well below the oceans. Just how deep this hidden water reaches, and how much of it exists, are the subjects of ongoing research.

Now a new study suggests that water may be more common than expected at extreme depths approaching 400 miles and possibly beyond – within Earth’s lower mantle. The study, which appeared March 8 in the journal Science, explored microscopic pockets of a trapped form of crystallized water molecules in a sampling of diamonds from around the world.

Diamond samples from locations in Africa and China were studied through a variety of techniques, including a method using infrared light at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). Researchers used Berkeley Lab’s Advanced Light Source (ALS), and Argonne National Laboratory’s Advanced Photon Source, which are research centers known as synchrotron facilities.

>Read more on the Advanced Light Source website

Photo: Oliver Tschauner, professor of research in the Department of Geoscience at the University of Nevada, Las Vegas, holds a diamond sample during a recent round of experiments at Berkeley Lab’s Advanced Light Source.
Credit: Marilyn Chung/Berkeley Lab

Possible Path to the Formation of Life’s Building Blocks in Space

Experiments at Berkeley Lab’s Advanced Light Source reveal how a hydrocarbon called pyrene could form near stars

Scientists have used lab experiments to retrace the chemical steps leading to the creation of complex hydrocarbons in space, showing pathways to forming 2-D carbon-based nanostructures in a mix of heated gases.

The latest study, which featured experiments at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), could help explain the presence of pyrene, which is a chemical compound known as a polycyclic aromatic hydrocarbon, and similar compounds in some meteorites.

A team of scientists, including researchers from Berkeley Lab and UC Berkeley, participated in the study, published March 5 in the Nature Astronomy journal. The study was led by scientists at the University of Hawaii at Manoa and also involved theoretical chemists at Florida International University.

>Read more on the Advanced Light Source website

Image: A researcher handles a fragment and a test tube sample of the Murchison meteorite, which has been shown to contain a a variety of hydrocarbons and amino acids, in this photo from a previous, unrelated study at Argonne National Laboratory. Experiments at Berkeley Lab are helping to retrace the chemical steps by which complex hydrocarbons like pyrene could form in the Murchison meteorite and other meteorites.
Credit: Argonne National Laboratory

Scientists confirm speculation on the chemistry of a high-performance battery

X-ray experiments at Berkeley Lab reveal what’s at work in an unconventional electrode.

Scientists have discovered a novel chemical state of the element manganese. This chemical state, first proposed about 90 years ago, enables a high-performance, low-cost sodium-ion battery that could quickly and efficiently store and distribute energy produced by solar panels and wind turbines across the electrical grid.

This direct proof of a previously unconfirmed charge state in a manganese-containing battery component could inspire new avenues of exploration for battery innovations.

X-ray experiments at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) were key in the discovery. The study results were published Feb. 28 in the journal Nature Communications.

Scientists at Berkeley Lab and New York University participated in the study, which was led by researchers at Natron Energy, formerly Alveo Energy, a Santa Clara, California-based battery technology company.

The battery that Natron Energy supplied for the study features an unconventional design for an anode, which is one of its two electrodes. Compared with the relatively mature designs of anodes used in lithium-ion batteries, anodes for sodium-ion batteries remain an active focus of R&D.

>Read more on the Advanced Light Source website

Photo: An array of solar panels and windmills.
Credit: PxHere