A New Way to “Squeeze” Infrared Light Down to Size

A New Way to “Squeeze” Infrared Light Down to Size

SCIENTIFIC ACHIEVEMENT

Using the Advanced Light Source (ALS), researchers demonstrated a new way to confine, or “squeeze,” infrared light by coupling photons with phonons (lattice vibrations) within a certain type of thin film.

SIGNIFICANCE AND IMPACT

The work heralds a new class of optical materials for controlling infrared light, with potential applications in photonics, sensors, and microelectronic heat management.

A light squeeze

Researchers have demonstrated that thin films of strontium titanate (SrTiO3, or STO) can confine, or “squeeze,” infrared light 10 times more than its bulk form can—a finding that holds promise for next-generation microelectronic and photonic devices. While this unusual behavior had been theoretically predicted for STO membranes, it had not yet been experimentally observed.

The researchers took advantage of advances in the synthesis of freestanding, large-scale crystalline oxide membranes, then used a combination of infrared micro- and nanospectroscopy to observe how infrared light couples to lattice vibrations in the membranes. They found that the coupling produced hybrid vibrational and electromagnetic waves (phonon polaritons) in the material, with different modes characterized by highly compressed wavelengths or greatly enhanced fields inside the sample.

Transferable membranes

Theoretical studies have suggested that ultrathin STO and other perovskite membranes can host highly confined surface phonon polaritons (SPhPs) with good propagation quality. Other compounds may have higher figures of merit, but because they are typically manually exfoliated, their lateral size is constrained to the micrometer range, which limits their potential for large-scale device fabrication.

Read more on ALS website

Image: In this experiment, an atomic force microscope tip focuses broadband synchrotron infrared light onto the surface of a strontium titanate (SrTiO3) membrane, just 100 nm thick. The infrared light excites phonon polaritons—quasiparticles that arise when light strongly interacts with dipole oscillations in the material’s lattice. Spectroscopic analysis of the scattered light enabled researchers to determine the properties of phonon polaritons on the material surface.

More Efficient Approach for Turning Plant Biomass into Useful Chemicals

More Efficient Approach for Turning Plant Biomass into Useful Chemicals

Editor’s note: The following article was originally issued by Georgia Institute of Technology. National Synchrotron Light Source II (NSLS-II) beamline scientist Eli Stavitski collaborated with researchers at Georgia Tech to evaluate their novel method of converting lignin, an organic polymer that gives wood and plants their strength, into valuable chemicals using the force of tiny steel balls instead of solvents. Using  X-ray absorption spectroscopy at the Inner-Shell Spectroscopy (ISS) beamline at NSLS-II, a U.S. Department of Energy (DOE) Office of Science User Facility at DOE’s Brookhaven National Laboratory, the team was able to establish the mechanism of the catalytic process that efficiently breaks the bonds of lignin compounds. For more information on Brookhaven’s role in this research, contact Denise Yazak (dyazak@bnl.gov, 631-344-6371).

Lignin is one of the most plentiful organic polymers on Earth, making up about 20 to 30 percent of the dry mass of wood and other plants. 

Despite this abundance, lignin’s complex structure has challenged researchers in breaking it down into useful components that can be used in the sustainable production of chemicals, plastics, and fuels. Therefore, lignin is often discarded as waste during the production of paper and other plant-based products.

However, researchers at the Georgia Institute of Technology have developed an approach that could transform lignin into valuable chemicals more efficiently than ever before.

The researchers published their findings in the journal ACS Sustainable Chemistry & Engineering on using a method known as mechanocatalysis, which uses physical forces, such as vibration or rotation, in a ball mill to drive chemical reactions without the need for solvents, heat, or high pressure.

Carsten Sievers, a professor in Georgia Tech’s School of Chemical and Biomolecular Engineering, explained that the first step in a lignin biorefinery is depolymerization, which breaks lignin down into small molecules. 

“Unfortunately, many depolymerization processes require the use of solvents, and separating the products from solvents, catalysts, and contaminants can be complicated, energy intensive, and leave behind waste,” Sievers said. 

“One way to reduce the need for these separation steps is to perform lignin depolymerization in a ball mill where collision with steel balls create environments that enable solid-state reactions without the need for solvents or liquid phases.”

Read more on BNL website

Image: Illustration of a mechanical impact that creates a reactive environment for depolymerization of biomass into value-added chemicals.

A greener possibility using lanthanide separation in two dimensions

A greener possibility using lanthanide separation in two dimensions

The lanthanides and other rare earth elements (REEs) aren’t really “rare” in the strict sense, but they are quite difficult to separate and purify from the other materials with which they’re usually found. Because of the great value and utility of these metals for many purposes, including electronics, computing, and various industrial processes that rely on their unique electronic and chemical properties, that difficulty is a major problem. 

Most current processes for REE separation and purification involve organic and acidic materials, making them both energy-intensive and environmentally unfriendly. Finding better separation techniques is therefore a pressing challenge. Researchers from the University of Chicago, Northwestern University, and Argonne National Laboratory took inspiration from nature to examine a new possibility for lanthanide separation. Their work was published in Science Advances. 

Noting that ion channels in cell membranes are capable of separating ions across cell membranes with great efficiency, speed and selectivity, the investigators chose to model this process with chemically functionalized inorganic membranes to see if REE purification could be accomplished in a similar way.  They constructed two-dimensional angstrom-scale artificial ion channels using MoS2 nanosheets that were covalently functionalized with acetic acid to generate MoS2-COOH membranes for lanthanide ion separation. 

The ion transport process was studied using a variety of tools, including electron microscopy, infrared spectroscopy, molecular dynamics simulations and X-ray absorption spectroscopy and X-ray diffraction studies. Data were collected at the DuPont-Northwestern-Dow Collaborative Access Team 5-BM-D beamline at the Advanced Photon Source, a U.S. Department of Energy (DOE) user facility at DOE’s Argonne National Laboratory.

Read more on Argonne website

Ending the cold chain: novel hydrogel set to improve access to vital medicines

Ending the cold chain: novel hydrogel set to improve access to vital medicines

Hydrogel enables fridge-free stabilisation of protein-based therapeutics without additives

The storage and distribution of vital protein therapeutics presents several complex challenges. Many medicines and vaccines need stable, temperature-controlled environments and chemical additives (excipients) such as preservatives to keep them effective and safe for use.  

This requires cold storage infrastructure and reliable energy sources which not only puts the responsibility on the user but causes accessibility and affordability challenges, especially in developing countries where resources are limited.  

Now researchers from the UK Universities of Manchester, Glasgow and Warwick have designed the world’s first hydrogel technology for the storage and distribution of crucial medicines and other biopharmaceuticals without the need for refrigeration or chemical additives. The aim is to provide more robust and equitable storage and delivery systems, benefitting everyone worldwide. 

The novel hydrogel cargo-system paves the way for affordable, energy efficient and user-friendly ways of supplying patients and clinics with vital protein-based drugs for health conditions like diabetes and cancer. The hydrogel also offers exciting potential for diagnostics and biotechnology. 

Published in the journal Nature on 24 July 2024, the research involved a series of tests to show how the hydrogel works on two proteins: insulin to treat diabetes, and beta-galactosidase, an enzyme with life science and biotechnology applications. Synchrotron science played an important role in the early development and testing of the hydrogel using Diamond’s I22 (Fig.1) and B21 (Fig.2) beamlines.  

The research was supported with funding from the European Union’s Horizon 2020 programme, the European Research Council, the Royal Society, the Engineering and Physical Sciences Research Council (EPSRC), the University of Glasgow, and UK Research and Innovation (UKRI). 

Read more on Diamond website

Image: Initial gel studies. Images exemplifying the syringe filter release protocol for gels. The gel is first loaded in a syringe fitted with a 0.22 μm filter. The gel is passed through the filter by gentle extrusion, releasing a clear solution. a.u., arbitrary units; CD, circular dichroism.

EBS flux reveals fate of over-compressed water

EBS flux reveals fate of over-compressed water

ESRF users have exploited the high X-ray flux of the EBS to confirm that water freezes into a particular ‘cubic’ form of ice when it is compressed very quickly. Published in Nature Communications, the results clear up a long-standing mystery in high-pressure physics, and will provide insights into the composition of the Solar System’s icy moons.

Water is so familiar to us that the ancients considered it one of the four basic elements. To modern physicists, however, it is a marvel – a liquid that, unlike almost all others, becomes not easier but harder to solidify at high pressures and, when it does solidify, expands rather than contracts. The behaviour results from the way the constituent hydrogen atoms bond with one another, and is vital for life. Without it, lakes and seas would freeze from the bottom up, killing everything inside.

In fact, the freezing of water is even more complicated than this. Under various pressures and temperatures, water is known to form at least 19 distinct phases of ice. The one we know well on Earth has its oxygen and hydrogen atoms in hexagonal rings. On the other hand, the most common phase in the Universe is likely to be a type of low-density amorphous ice, without any long-range crystal structure at all. Another very common phase with big scientific interest is the cubic-bonded ice VII, which is stable over a vast pressure range from 2 to 80 gigapascals, equivalent to those present on icy planets and moons.

The gateway to ice VII may be higher pressures, but the speed of compression is critical. Take it slowly, and normal water freezes at about one gigapascal into ice VI, a tetrahedral phase, before forming ice VII at about 2 gigapascals. Go faster, though, and the freezing is waylaid, occurring at higher and higher pressures.

Until now, no-one has been sure what water ultimately freezes into when it is compressed very quickly. The answer is important, because the freezing of water on other planets and moons could have taken place when it was over-compressed during planetary impact.

Charles Pépin, Paul Loubeyre  and colleagues at the CEA Laboratory for Materials at Extreme Conditions at the Université Paris-Saclay in France, together with scientists at the ESRF in France and the Paul Scherrer Institute (PSI) in Switzerland, have finally solved the mystery using a range of cutting-edge instrumentation for time-resolved X-ray diffraction.

One part of the toolkit was a special “dynamic-piezo” diamond anvil cell (d-DAC), designed by the CEA team to compress water in a well-controlled manner. Another was the latest Jungfrau detector – the result of a joint PSI–ESRF development – which can record an X-ray image every few microseconds. Most importantly, however, was the extremely high flux of X-rays streaming through the ID09 beamline, provided by the EBS.

Read more at ESRF beamline

30 years of ESRF users: Pioneering science

30 years of ESRF users: Pioneering science

On this 1st October the ESRF celebrates 30 years of science and user operation. When the ESRF officially opened its doors to users in 1994, it offered 15 state-of-the-art beamlines and capabilities based on a state-of-the-art synchrotron source. Three decades later, and with a record of discoveries in its history, the ESRF enters a new era of scientific possibilities with EBS.

Thirty years ago, just one day after its official inauguration on 30 September 1994, the first users came to the ESRF to begin their experiments. Since then, the ESRF has contributed to over 40,000 publications and four Nobel Prizes, driving the frontiers of science across numerous fields.

Among the first users was Jean Daillant, the new ESRF director general. “When I first came as a user to the ESRF, back in 1994, it was a unique place to carry out experiments we could only have imagined before, and this experience definitely shaped my career”, explains Daillant.

During these three decades, the ESRF users have been coming onsite with ever more complex scientific questions to answer, while the scientists, engineers and technicians in-house have made use of their creativity to implement the best set-ups to achieve what one day seemed unachievable.

Long-term user and former member of the Science Advisory Committee Moshe Deutsch, professor at Bar-Ilan University (Israel), explains the importance of this collaboration: “Suggestions coming from the users to the beamline scientists and up to the committees and management, i.e. bottom up, along with the combined expertise of the users and the staff, are, and have always been at the ESRF, the seeds of new directions for science, for instrumentation and for beamlines”. 

The number of proposals throughout these years has increased exponentially: In 1995, there were 792 proposals. In 2024, there were a total of 2200. Joanne McCarthy, head of the User Office, explains how the beamtime proposals have become more sophisticated: “Today scientists need to get a full picture of a scientific question, and thanks to EBS and the different access modes, there is an increasing number of proposals that include experiments using complementary techniques and with teams including different expertise”.  An example of this is the Human Organ Atlas Hub, where interdisciplinary groups made of doctors, physicists and engineers join forces to provide unprecedented insights into our bodies in health, ageing and disease.

Pioneering research

Back in 1994, the ESRF was one of the very first 3rd generation synchrotrons and could provide higher flux than previously built machines, which allowed several fields to really take off.

One of the clearest examples is structural biology, which was already popular in the early days (1/3 of the proposals submitted), leading to several Nobel Prize laureates from the user community.

“The ESRF is the facility where we collected our best data. This is where we did our real science,” said Ada Yonath, winner of the Nobel prize in chemistry in 2009. And Sir Venki Ramakrishnan, Nobel prize winner in chemistry in 2009 and President of the Royal Society, added: “The ESRF was an essential ingredient of our work on the structure of the ribosome. I think when you have a large international facility, you can do things on a scale that is not possible by just one country. The ESRF, because it has been international, has brought top scientists together from different countries, and this has led to a lot of pioneering ideas.”

Throughout the years, cryo macromolecular crystallography became a key success of structural biology, but a significant limitation is that the crystals were not in their natural environment. Today, thanks to EBS, the ESRF offers room-temperature serial crystallography, which enables the capture of crystal structures in conformations closer to ‘native’ conditions, allowing scientists to follow reactions in real-time. These new capabilities are very relevant for the design of new drugs and biotechnological applications.

Another field where the ESRF was a pioneer is paleontology. The first experiments were carried out in the year 2000 by Paul Tafforeau, PhD student at the time, when José Baruchel, in charge of the X-ray microtomography beamline, gave him the chance to scan some fossil teeth. “Until then I had used destructive methods, which are not convenient for unique specimens like fossils”, explains Tafforeau, who is now in charge of BM18. “Every time I had beamtime it felt like a whole new world opened up”.

The ESRF soon became the referent for research in paleontology, where the oldest sample scanned are 2.8 billion year old bacteria. In the beginning, the sizes of the samples were no more than 1-2 cm, which increased to 16cm when the first scan of a hominid brain took place. Today, with the new BM18 and the EBS higher coherence and energy than previously, paleontologists will be able to scan 250 cm tall samples weighing around 300kg.

Read more on ESRF website

Replacing a component in a nuclear reactor

Replacing a component in a nuclear reactor

Installing a new component in a nuclear reactor could be compared to working in outer space repairing or replacing a part on the International Space Station.

The environment is unique, working conditions are difficult and awkward and all the extensive preparation cannot prepare you for all the unexpected.  Like protocols in space, safety guides every action in the reactor environment.

The installation of a Cold Neutron Source (CNS), a component that reduces the energy and speed of the neutrons from a research reactor for use in scientific instruments, was successfully completed in September 2024. 

The OPAL Reactor Manager said that since OPAL began operations, the successful installation of the CNS is the most significant achievement the group has made as team.  It is a technical milestone with scientific, economic, and national significance. It confirms that OPAL is one of the best and most advanced reactors in the world and will continue to bring benefits in the peaceful uses of nuclear science and technology to Australia. 

The new and improved cold neutron source offers ANSTO greater levels of scientific capability. Cold neutrons allow scientists to investigate the unique properties of larger molecules such as proteins and polymers.

Replacement of the cold neutron source is a major milestone for ANSTO, demonstrating our expertise in engineering design and major maintenance activities.

Chronology

.Planning and design activities commenced in 2015, working towards the 2024 shutdown timeline.  The Cold Neutron Source was replaced over a shutdown period which extended from March to September 2024. 

Andrew Eltobaji has been the project manager of the CNS upgrade since its conception, working closely with 20 core team members but drawing on the expertise of 30 to 40 more contributors from diverse disciplines across ANSTO.

The specialist Engineering, Maintenance and Operations team was made up of nuclear engineers, reactor managers and supervisors, technicians, welders, and radiation safety experts.

In the planning stages, the team reached out to several other international research reactors to identify what other facilities had undertaken similar major shutdown activities. This investigation quickly identified that the planned Cold Neutron Source replacement was a unique activity not undertaken by other research reactor facilities.  This resulted in the majority of design development work and maintenance activities being undertaken by ANSTO engineering and maintenance experts. 

To prepare technicians for the operation, a full-scale mock-up of the CNS and reactor environment was constructed to assist in the planning and training of supervisors and technicians. This allowed team members to undertake comprehensive training in conditions which mimicked the real environment. 

The mock-up enabled the team to develop the process for replacing the CNS and develop the specialist tooling required.

The training mock-up facility was used to rehearse the CNS installation activities in a simulated environment and allowed them to complete tasks safely. A team of supervisors were trained using the mock-up to prepare them for their training of technicians.

During the engineering design process, every component in the installation was modelled in a 3D computer simulation. This was used to fabricate prototype components to initially build the full-scale mock-up then used to optimise the design of the CNS itself.

Prior to the commencement of the installation sequence, the level of water in the reactor pool was reduced and a number of reactor components, including pipework, had to be removed to allow access to the old CNS.

The CNS together with associated pipework were lifted out of the reactor and placed in a special shielded device with precision. This was done remotely using cameras and no direct interaction with technicians.

The replacement CNS structure was eight metres tall and had to be installed precisely vertical. Again, this was conducted remotely using cameras and required positioning accuracy to within a few millimetres. Once in place, the various pipes suppling either helium, deuterium or vacuum services were connected and tested. 

The CNS Cryogenic refrigeration system cools helium down to -253°C, which in turn liquifies deuterium, which has a cooling effect on the neutrons.

Many measures were in place to ensure the safety of maintenance technicians.

Read more on ANSTO website

New upgrade will supercharge atomic vision of the world’s most powerful X-ray laser

New upgrade will supercharge atomic vision of the world’s most powerful X-ray laser

The high-energy upgrade will keep the U.S. at the forefront of X-ray science and technology, allowing researchers to advance fields such as sustainability, human health and quantum information.

The Department of Energy (DOE) has given the green light for construction to begin on a high-energy upgrade that will further boost the performance of the Linac Coherent Light Source (LCLS), the world’s most powerful X-ray free-electron laser (XFEL) at the DOE’s SLAC National Accelerator Laboratory. When complete, the upgrade will allow scientists to explore atomic-scale processes with unprecedented precision and address fundamental questions in energy storage, catalysis, biology, materials science and quantum physics like never before.

“This high-energy upgrade to LCLS strengthens the lab’s position as a world leader in X-ray and ultrafast science,” said SLAC Lab Director John Sarrao. “With the critical support of the Department of Energy’s Office of Science and our partner labs, the upgrade, when complete, will open new avenues for scientific discovery and innovation. This will continue to attract top talent and foster groundbreaking research across multiple disciplines.”

In 2023, SLAC celebrated completion of the LCLS-II project, taking X-ray science to a whole new level with the addition of a superconducting accelerator, two new magnetic structures, called undulators, to generate soft and hard X-rays from the electron beam, and other major leaps in technology that allow the facility to produce up to a million X-ray pulses per second – 8,000 times more than its predecessor.

The new upgrade project, called LCLS-II-HE, will double the energy of the electron beam coming out of the superconducting electron accelerator, which will more than double the maximum X-ray energy and deliver a 3,000-fold performance increase in average X-ray brightness for “hard,” or high-energy, X-rays. 

“The LCLS-II-HE upgrade will be a transformative advance for the scientific mission of DOE Basic Energy Sciences and the broader scientific community,” said LCLS Director Mike Dunne. “If the LCLS-II upgrade enabled a high-quality movie camera capable of capturing clear and detailed images, the LCLS-II-HE upgrade greatly boosts that camera’s resolution and sensitivity. Scientists will be able to image the atomic-scale motion of materials, chemical systems and biological complexes to address some of the most critical challenges facing our society.”

With favorable Critical Decisions 2 and 3 (CD-2/3) in September 2024, DOE has formally approved construction of the $716M project, representing a significant advancement in X-ray laser technology.

Read more on SLAC website

Alternating currents for alternative computing with magnets

Alternating currents for alternative computing with magnets

A new study conducted at the University of Vienna, the Max Planck Institute for Intelligent Systems in Stuttgart, and the Helmholtz Centers in Berlin and Dresden takes an important step in the challenge to miniaturize computing devices and to make them more energy-efficient. The work published in the renowned scientific journal Science Advances opens up new possibilities for creating reprogrammable magnonic circuits by exciting spin waves by alternating currents and redirecting these waves on demand. The experiments were carried out at the Maxymus beamline at BESSY II.

The central processing units (CPUs) that we use in our laptops, desktops or even phones are using billions of transistors, which are based on the complementary metal oxide semiconductor (CMOS) technology. With the increasing need to miniaturize these devices, several physical limitations are raising concerns for their sustainability. In addition, high power consumptions and energy losses, push scientists to search for alternative computing architectures.

One of the promising candidates are magnons, the quanta of spin waves. “Imagine a calm lake. If we let a stone fall into water, the resulting waves will propagate away from the point of generation. Now, we replace the lake with a magnetic material and the stone with an antenna. The propagating waves are called spin waves and can be used to transfer energy and information from one point to another with minimal losses,” says Sabri Koraltan from the University of Vienna, first author of the recent study published in the journal Science Advances. Once generated, the spin waves can be used for magnonic devices to perform classical and unconventional computing tasks. “To reduce the footprint of magnonic devices, we need to use spin waves with short wavelengths, which are difficult to generate using state-of-the-art nano antennas due to limited efficiency,” adds Sebastian Wintz from Helmholtz-Zentrum Berlin and the coordinator of the research project. Nano antennas can only be fabricated in clean rooms, highly specialized nanofabrication facilities, using advanced lithography techniques. 

Read more on HZB website

Isolating active sites for more efficient catalysts

Isolating active sites for more efficient catalysts

Scientists are always searching for new catalysts to enable fast, energy-efficient chemical reactions to transform wastes into useful chemical fuels, such as converting carbon dioxide to methane. Single-site catalysts are a promising new class of catalyst, with well-defined, well-designed structures where each reaction site is isolated. The challenge with such materials is that the active catalytic sites, which can be as small as a single atom, tend to aggregate, degrading their efficiency and selectivity. 

Now researchers using the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science user facility at DOE’s Argonne National Laboratory, have demonstrated a design for such single-site catalysts that resist aggregating and retain their high efficiency.

The design starts with polyoxometalate clusters (POMs). These are discrete polyatomic anions in which three or more metals, including molybdenum, share oxygen atoms. Catalytic atoms, often noble metals such as platinum or rhodium, can be embedded with the POM. The POM essentially belts the single-site catalyst atom in place, so it has difficulty interacting with other catalytic sites.

But for the catalyst to be efficient, reacting molecules need to be able reach the active site, so the next step is to disperse them through a support with high surface area. In this case, the researchers used a zirconium-based metal-organic framework (MOF), a porous architecture that contains a high surface area within a small volume. This dual-confinement strategy allows the researchers to achieve a relatively high density of active sites, up to 3.2 weight percent, without the sites sintering together during use.

One previous strategy to prevent aggregation of the catalytic atoms had been to spread them far apart on a support material. That made it difficult to assess the structure of the catalysts. The high catalyst loading that is stable using the POM-MOF approach provides sufficient signal to see the catalyst sites using X-rays. The team used pair distribution function analysis (PDF) a technique that is a specialty of beamline 11-ID-B at the APS. PDF provides the structure and relative geometry of the atoms that make up the active catalyst site. Researchers heated samples of their material to 200 °C and used scattering measurements to determine the structure of the POMs when they entered an active state.

The team also performed X-ray absorption spectroscopy (XAS) at beamline 5-BM-D, the Dupont-Northwestern-Dow Collaborative Access Team (DND-CAT) beamline. This technique provides element-specific information, allowing them to isolate the platinum and the rhodium environments. Combining the PDF and XAS measurements allowed the researchers to figure out the local geometry of the catalyst’s active site during the catalytic reaction. They found, for instance, that the distance between the rhodium or platinum and the molybdenum in the active catalyst was shorter than the metal-to-metal bond lengths in bulk metals. 

Researchers were able to compare their experimental data with computer simulations and say which of almost 100 computer-generated models most closely matched their results. Now that they’ve identified the structure of their single-site catalysts and refined the models, they can undertake further computational studies to explore what other formulations might be most promising, before trying to synthesize them. 

Armed with this new understanding of POMs, scientists can now explore whether there are different versions that might achieve high efficiency while using cheaper or more abundant metals than platinum, making chemical reactions more energy and cost efficient. – Neil Savage

See: Z. Chen1, S.M.G. Rabbani2, Q. Liu3,4, W. Bi3,4, J. Duan3, Z. Lu3, N.M. Schweitzer3, R.B. Getman2, J.T. Hupp2, K.W. Chapman1, “Atomically precise single-site catalysts via exsolution in a polyoxometalate-metal-organic framework architecture,” Journal of the American Chemical Society 2024, 146, 12, 7950-7955 (March 2024)

Author affiliations: 1Stony Brook University; 2Clemson University; 3Northwestern University; 4University of Science and Technology of China

This work was initially supported as part of the Inorganometallic Catalyst Design Center, an Energy Frontier Research Center (EFRC) funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences (DE-SC0012702), and subsequently as part of the Catalyst Design for Decarbonization Center EFRC (DE-SC0023383). Q.L. and W.B. acknowledge the financial support as visiting scholars from the National Natural Science Foundation of China (No. 11705205, No. 22175051). This research used the beamline 5-BM-D for X-ray adsorption spectroscopy and 11-ID-B for total scattering measurements at the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under contract no. DE-AC02-06CH11357. This research used ambient pressure XPS of the Center for Functional Nanomaterials (CFN), which is a U.S. Department of Energy Office of Science User Facility, at Brookhaven National Laboratory under Contract No. DE-SC0012704. This work made use of the Reactor Engineering and Catalyst Testing (REACT) core facility of the Center for Catalysis and Surface Science at Northwestern University. The authors acknowledge Leighanne C. Gallington and Qing Ma for the help with remote measurements at the beamline. We thank Ashley R. Head for help with setting up the APXPS measurement. Q.L. thanks Yang Song and Wangsheng Chu for the analysis of XAS.

Read more at Argonne website

Image: A POM consisting of ring of molybdenum (purple)-oxygen (red) octahedra that surrounds a catalytically active rhodium (green) site, all supported on Zr-MOF. When the pristine catalyst (top) is activated under hydrogen at high temperature, its structure changes (bottom) and the Rh protrudes from the Mo-oxo ring.

Manganese Cathodes Could Boost Lithium-ion Batteries

Manganese Cathodes Could Boost Lithium-ion Batteries

Rechargeable lithium-ion batteries are growing in adoption, used in devices like smartphones and laptops, electric vehicles, and energy storage systems. But supplies of nickel and cobalt commonly used in the cathodes of these batteries are limited. New research led by the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) opens up a potential low-cost, safe alternative in manganese, the fifth most abundant metal in the Earth’s crust.

Researchers showed that manganese can be effectively used in emerging cathode materials called disordered rock salts, or DRX. Previous research suggested that to perform well, DRX materials had to be ground down to nanosized particles in an energy-intensive process. But the new study found that manganese-based cathodes can actually excel with particles that are about 1000 times larger than expected. The work was published Sept. 19 in the journal Nature Nanotechnology.

“There are many ways to generate power with renewable energy, but the importance lies in how you store it,” said Han-Ming Hau, who researches battery technology as part of Berkeley Lab’s Ceder Group and is a PhD student at UC Berkeley. “By applying our new approach, we can use a material that is both earth-abundant and low-cost, and that takes less energy and time to produce than some commercialized Li-ion battery cathode materials. And it can store as much energy and work just as well.”

The researchers used a novel two-day process that first removes lithium ions from the cathode material and then heats it at low temperatures (about 200 degrees Celsius). This contrasts with the existing process for manganese-based DRX materials, which takes more than three weeks of treatment.

Researchers used state-of-the-art electron microscopes to capture atomic-scale pictures of the manganese-based material in action. They found that after applying their process, the material formed a nanoscale semi-ordered structure that actually enhanced the battery performance, allowing it to densely store and deliver energy.

The team also used different techniques with X-rays to study how battery cycling causes chemical changes to manganese and oxygen at the macroscopic level. By studying how the manganese material behaves at different scales, the team opens up different methods for making manganese-based cathodes and insights into nano-engineering future battery materials.

Read more on ALS website

Image: A new process for manganese-based battery materials lets researchers use larger particles, imaged here by a scanning electron microscope. 

Credit: Han-Ming Hau/Berkeley Lab and UC Berkeley

Transistors and NASA’s radiation paradox

Transistors and NASA’s radiation paradox

The nature of Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs) present a fascinating paradox in space exploration. Their strength in radiation detection becomes their weakness in space operations, exposing an Achilles’ heel for NASA. Yet, these same devices monitor radiation doses received by humans – on earth and in space. 
 

These tiny transistors have transformed everything from consumer electronics to advanced scientific applications. They are essential components in radios, MP3 players and iPods, powered satellite communications and now drive the artificial intelligence age. Their unique ability to measure radiation by capturing changes in electrical characteristics when exposed to ionising radiation is critical in both space exploration and cancer treatment.  
 

Australia leads the development of MOSFET-based radiation detectors for radiation monitoring. In a recently published work, ANSTO scientists and collaborators showed how four MOSFETs can be used to precisely measure radiation doses that patients receive during Boron Neutron Capture Therapy (BNCT).

Ironically, this property that we rely on for measuring radiation nearly doomed NASA’s Europa Clipper mission, due to the risk of radiation damage compromising the operation of its MOFET-based systems. Understanding this dual interaction with radiation highlights the importance of innovative solutions in both space missions and healthcare. It is also a great example of how mission-based research impacts everyday life. 

The Versatility of MOSFETs 

MOSFETs are a key component in modern electronics. Following Moore’s Law, the number of transistors in a circuit has increased exponentially over time enabling more powerful and energy-efficient technologies. Companies like NVIDIA use billions of MOSFETs in their GPUs, such as the A100, which is the backbone of  high-performance AI systems. These transistors allow the efficient power management and rapid switching that is necessary for handling the complex operations in machine learning and AI applications,

In jointly published research, ANSTO and University of Wollongong (UOW) researchers used a Quad-MOSFET array to precisely measure radiation quality in boron neutron capture therapy (BNCT). Each MOSFET was coupled to a different moderator (material that interacts with radiation) and measures different energy levels to allow accurate radiation monitoring during treatment.  

Another example is the MOSkin dosimeter, developed at the Centre for Medical Radiation Physics at the University of Wollongong. MOSkin is a skin-mounted MOSFET device that provides real-time radiation dose measurements during radiotherapy. This technology is already being used in clinical settings to improve safety and accuracy in radiation treatments. 

MOSFETs in Space Exploration 

MOSFETs are integral to managing systems and instruments in spacecraft due to their efficiency and low power consumption. However, space environments, especially around Jupiter, expose these devices to intense radiation—a challenge NASA faced with the Europa Clipper mission.

The radiation delivers a harsh cocktail of ionising particles. This radiation can cause single event effects (SEE), where high-energy particles flip a MOSFET’s state from “on” to “off,” causing them to malfunction. It can also cause total ionising dose (TID) effects, a situation in which radiation slowly degrades the MOSFET’s performance by trapping charges and creating defects in the semiconductor material. 

Read more at ANSTO website

Scientific discoveries: Acynodon between Technology and Palaeontology

Scientific discoveries: Acynodon between Technology and Palaeontology

A major study conducted at the paleontological site of Villaggio del Pescatore, in Friuli-Venezia Giulia, has revealed new information on the appearance of the Italian territory at the time of the dinosaurs. This project, a collaboration between the Municipality of Trieste and Zoic s.r.l., led to the extraction and preparation of numerous fossil finds, including those of the rare crocodile Acynodon, a semi-aquatic reptile that lived during the Cretaceous period.
Cooperation with Elettra revealed previously unseen details of Acynodon’s skull that were impossible to obtain before without damaging the fossil. Although similar to a small crocodile, its teeth are surprising: the front teeth are adapted to grasp small prey, while the massive, rounded rear teeth shred shells. This unique adaptation suggests that the Cretaceous crocodiles at the Fisherman’s Village were very different in size, shape and diet to those of today. The results of the research were published in the scientific journal The Anatomical Record (Muscioni et al., 2024).

Read more on Elettra website

Artificial intelligence explores the underground

Artificial intelligence explores the underground

Researchers at the Paul Scherrer Institute PSI have shown that artificial neural networks have the potential to determine very precisely the characteristics of rock layers, like their mineralogical composition, solely on the basis of drill core images. This could speed up future geological investigation efforts while simultaneously optimising costs. 

Underground investigations are often time-consuming and costly. Yet without knowledge of the properties and characteristics of the layers located deep below the surface, many important questions cannot be answered: Can data for future explorations around the deep geological repository be predicted quickly and reliably? Is a particular underground site suitable for obtaining deep geothermal heat and power, or for extracting natural gas? Are the geological conditions at a depth of 1,500 metres suitable for storing carbon dioxide? To make it easier to answer these and other questions, Romana Boiger, from the Laboratory for Waste Management in the PSI Center for Nuclear Engineering and Sciences, is working to establish new tools from the area of artificial intelligence for geological investigations.

Boiger’s attention is focused on so-called artificial neural networks in particular. These consist of several layers of interconnected artificial neurons. These are, in the final analysis, mathematical formulas that process input data and deliver a result. What makes this special is that artificial neural networks are capable of learning. For example, an artificial neural network that is supposed to distinguish between apples and pears can be trained by presenting it with images of apples and pears and simultaneously providing the correct interpretation. After a certain number of training runs, the artificial neural network is then prepared to correctly classify even unfamiliar pictures of apples and pears.

In her research, Boiger, a mathematician with a focus on data science and machine learning, uses a special type of artificial neural networks called convolutional neural networks (CNNs). These are especially well suited to the identification and analysis of patterns and simple features in images.

Scientifically uncharted territory

One novel application of CNNs is the subject of the study Boiger and colleagues published in May 2024 in the Swiss Journal of Geosciences. It is the result of an interdisciplinary collaboration between scientists from PSI and experts in geology and engineering at Nagra. In a first step, they used CNNs to analyse images of drill cores taken from the Trüllikon borehole in Northern Switzerland. This was part of Nagra’s site investigation programme to identify a suitable site for a deep geological repository. The test interval was selected from 55 metres of drill core from a depth of between 770 and 939 metres. «We wanted to find out if it’s possible to accurately determine the lithological formations and above all the mineralogical composition of the rock – such as the proportions of calcite, clay, and silicates – solely on the basis of drill core images. » Studies already exist to investigate the lithology, determining properties that can be observed with the naked eye, without the help of a microscope. On the other hand, determining mineralogy in this way is scientifically uncharted territory. «No one had ever done it this way before.»

For her research, Boiger used artificial neural networks that had already been trained. They had previously learned to distinguish between images of vehicles, animals, people, and fruit – as well as geological formations and rocks – using images from the ImageNet database, a collection of more than 14 million images.

The CNN models thus already had a certain knowledge base when they were presented with the Trüllikon drill cores. The 10 cm thick drill cores from various geological units, known as formations, were systematically photographed after washing. The photographs were then cut into slices. Boiger and colleagues proceeded step by step: They expanded the pre-trained CNN by a few layers, which they then specifically trained to distinguish between lithological formations on the basis of the images. This resulted in a new, larger CNN model. It was then expanded again by a few layers – and finally trained to recognise the mineralogical composition.

Read more on PSI website

Image: Romana Boiger wants to use artificial intelligence to improve the exploration of deep earth layers and the analysis of drill cores.

Credit: Paul Scherrer Institute PSI/Markus Fischer

Discovering a New Dimension in Skyrmion Dynamics

Discovering a New Dimension in Skyrmion Dynamics

A new study led by Professor Shilei Zhang from ShanghaiTech University, involving the University of Oxford and Diamond Light Source, has uncovered a groundbreaking phenomenon in the dynamics of magnetic skyrmions, which are topologically protected spin textures with particle-like properties. Traditionally, skyrmions have been understood to move linearly in response to external stimuli. However, the research team’s innovative approach using a linear temperature gradient has revealed a new, continuous rotational motion within skyrmion crystallites, driven by a novel chiral lattice torque.

Skyrmion crystallites as rigid entities

Magnetic skyrmions are known for their potential as information carriers in spintronics due to their stability, low-energy transport cost and nanoscale size. As for conventional magnetic information carriers, speed is key so the study of their dynamics is an important task on their way to device applications. In certain chiral magnets, skyrmions condense into a skyrmion lattice – a two-dimensional, closely-packed hexagonal arrangement. Unlike isolated skyrmions, this condensed skyrmion lattice exhibits a unique rigidity, meaning that the packed skyrmion structure resists to be broken up into its constituent parts. Under inhomogeneous driving forces, however, the strain on the skyrmion lattice becomes large enough to break the perfect lattice up into finite-size skyrmion crystallites. The team’s experimental work demonstrated that when subjected to a linear temperature gradient, these skyrmion crystallites do not merely translate; they also rotate, a motion analogous to a rolling ball or drifting sheets of ice in the ocean, combining both translational and rotational dynamics.

Experimental breakthrough with resonant elastic X-ray scattering

Utilising time- and spatially-resolved resonant elastic X-ray scattering (REXS) at beamline I10, the researchers observed this rotational behaviour in the insulating chiral magnet Cu2OSeO3. Their experiments provided direct evidence of the chiral lattice torque’s role in driving the skyrmion crystallites’ rolling motion. The skyrmion crystallites displayed a uniform rotational chirality, which could be reversed by flipping the direction of the applied magnetic field, confirming the theoretical predictions.

Read more on Diamond website

BESSY II: Heterostructures for Spintronics

BESSY II: Heterostructures for Spintronics

Spintronic devices work with spin textures caused by quantum-physical interactions. A Spanish-German collaboration has now studied graphene-cobalt-iridium heterostructures at BESSY II. The results show how two desired quantum-physical effects reinforce each other in these heterostructures. This could lead to new spintronic devices based on these materials.

Spintronics uses the spins of electrons to perform logic operations or store information. Ideally, spintronic devices could operate faster and more energy-efficiently than conventional semiconductor devices. However, it is still difficult to create and manipulate spin textures in materials.

Graphene for Spintronics

Graphene, a two-dimensional honeycomb structure build by carbon atoms, is considered an interesting candidate for spintronic applications. Graphene is typically deposited on a thin film of heavy metal. At the interface between graphene and heavy metal, a strong spin-orbit coupling develops, which gives rise to different quantum effects, including a spin-orbit splitting of energy levels (Rashba effect) and a canting in the alignment of spins (Dzyaloshinskii-Moriya interaction). Especially the spin canting effect is needed to stabilise vortex-like spin textures, known as skyrmions, which are particularly suitable for spintronics.

Plus Cobalt Monolayers

Now, however, a Spanish-German team has shown that these effects are significantly enhanced when a few monolayers of the ferromagnetic element cobalt are inserted between the graphene and the heavy metal (here: iridium). The samples were grown on insulating substrates which is a necessary prerequisite for the implementation of multifunctional spintronic devices exploiting these effects.

Read more on HZB website

Image: Symbolic illustration of a graphene layer on a microchip. In combination with a heavy-metal thin film and ferromagnetic monolayers, graphene could enable spintronic devices.

Credit: Dall-E/arö