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  • richardmitnick 10:10 pm on April 16, 2014 Permalink | Reply
    Tags: , , , , X-ray Technology   

    From SLAC Lab: “Scientists Capture Ultrafast Snapshots of Light-driven Superconductivity” 

    April 16, 2014
    No Writer Credit

    A new study pins down a major factor behind the appearance of superconductivity – the ability to conduct electricity with 100 percent efficiency – in a promising copper-oxide material.

    Scientists used carefully timed pairs of laser pulses at SLAC National Accelerator Laboratory’s Linac Coherent Light Source (LCLS) to trigger superconductivity in the material and immediately take X-ray snapshots of its atomic and electronic behavior as superconductivity emerged.

    und
    The Undulator Hall at SLAC’s Linac Coherent Light Source X-ray laser. (Brad Plummer/SLAC)

    They discovered that so-called “charge stripes” of increased electrical charge melted away as superconductivity appeared. Further, the results help rule out the theory that shifts in the material’s atomic lattice hinder the onset of superconductivity.

    Armed with this new understanding, scientists may be able to develop new techniques to eliminate these charge stripes and help pave the way for room-temperature superconductivity, often considered the holy grail of condensed matter physics. The demonstrated ability to rapidly switch between the insulating and superconducting states could also prove useful in advanced electronics and computation.

    The results, from a collaboration led by scientists from the Max Planck Institute for the Structure and Dynamics of Matter in Germany and the U.S. Department of Energy’s SLAC and Brookhaven national laboratories, were published online April 16, 2014, in the journal Physical Review Letters.

    “The very short timescales and the need for high spatial resolution made this experiment extraordinarily challenging,” said co-author Michael Först, a scientist at the Max Planck Institute. “Now, using femtosecond X-ray pulses, we found a way to capture the quadrillionths-of-a-second dynamics of the charges and the crystal lattice. We’ve broken new ground in understanding light-induced superconductivity.”

    Josh Turner, an LCLS staff scientist, said, “This represents a very important result in the field of superconductivity using LCLS. It demonstrates how we can unravel different types of complex mechanisms in superconductivity that have, up until now, been inseparable.”

    He added, “To make this measurement, we had to push the limits of our current capabilities. We had to measure a very weak, barely detectable signal with state-of-the-art detectors, and we had to tune the number of X-rays in each laser pulse to see the signal from the stripes without destroying the sample.”

    Ripples in Quantum Sand

    The compound used in this study was a layered material consisting of lanthanum, barium, copper, and oxygen grown at Brookhaven Lab by physicist Genda Gu. Each copper oxide layer contained the crucial charge stripes.

    man
    Physicist Genda Gu in the Brookhaven Lab facility where the copper-oxide materials were grown for this study.

    “Imagine these stripes as ripples frozen in the sand,” said John Hill, a Brookhaven Lab physicist and coauthor on the study. “Each layer has all the ripples going in one direction, but in the neighboring layers they run crosswise. From above, this looks like strings in a pile of tennis racquets. We believe that this pattern prevents each layer from talking to the next, thus frustrating superconductivity.”

    To excite the material and push it into the superconducting phase, the scientists used mid-infrared laser pulses to “melt” those frozen ripples. These pulses had previously been shown to induce superconductivity in a related compound at a frigid 10 Kelvin (minus 442 degrees Fahrenheit).

    “The charge stripes disappeared immediately,” Hill said. “But specific distortions in the crystal lattice, which had been thought to stabilize these stripes, lingered much longer. This shows that only the charge stripes inhibit superconductivity.”

    Stroboscopic Snapshots

    To capture these stripes in action, the collaboration turned to SLAC’s LCLS X-ray laser, which works like a camera with a shutter speed faster than 100 femtoseconds, or quadrillionths of a second, and provides atomic-scale image resolution. LCLS uses a section of SLAC’s 2-mile-long linear accelerator to generate the electrons that give off X-ray light.

    Researchers used the so-called “pump-probe” approach: an optical laser pulse strikes and excites (pumps) the lattice and an ultrabright X-ray laser pulse is carefully synchronized to follow within femtoseconds and measure (probe) the lattice and stripe configurations. Each round of tests results in some 20,000 X-ray snapshots of the changing lattice and charge stripes, a bit like a strobe light rapidly illuminating the process.

    To measure the changes with high spatial resolution, the team used a technique called resonant soft X-ray diffraction. The LCLS X-rays strike and scatter off the crystal into the detector, carrying time-stamped signatures of the material’s charge and lattice structure that the physicists then used to reconstruct the rise and fall of superconducting conditions.

    “By carefully choosing a very particular X-ray energy, we are able to emphasize the scattering from the charge stripes,” said Brookhaven Lab physicist Stuart Wilkins, another co-author on the study. “This allows us to single out a very weak signal from the background.”

    Toward Superior Superconductors

    The X-ray scattering measurements revealed that the lattice distortion persists for more than 10 picoseconds (trillionths of a second) – long after the charge stripes melted and superconductivity appeared, which happened in less than 400 femtoseconds. Slight as it may sound, those extra trillionths of a second make a huge difference.

    “The findings suggest that the relatively weak and long-lasting lattice shifts do not play an essential role in the presence of superconductivity,” Hill said. “We can now narrow our focus on the stripes to further pin down the underlying mechanism and potentially engineer superior materials.”

    Andrea Cavalleri, director of the Max Planck Institute, said, “Light-induced superconductivity was only recently discovered, and we’re already seeing fascinating implications for understanding it and going to higher temperatures. In fact, we have observed the signature of light-induced superconductivity in materials all the way up to 300 Kelvin (80 degrees Fahrenheit) – that’s really a significant breakthrough that warrants much deeper investigations.”

    Other collaborators on this research include the University of Groningen, the University of Oxford, Diamond Light Source, the Lawrence Berkeley National Laboratory, Stanford University, the European XFEL, the University of Hamburg and the Center for Free-Electron Laser Science.

    The research conducted at the Soft X-ray Materials Science (SXR) experimental station at SLAC’s LCLS – a DOE Office of Science user facility – was funded by Stanford University, Lawrence Berkeley National Laboratory, the University of Hamburg and the Center for Free-Electron Laser Science (CFEL). Work performed at Brookhaven Lab was supported by the DOE’s Office of Science.

    See the full article here.

    SLAC Campus
    SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the DOE’s Office of Science.
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  • richardmitnick 8:37 am on March 30, 2014 Permalink | Reply
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    From Brookhaven Lab: “Make Way for ABBIX” 

    Brookhaven Lab

    March 26, 2014
    Mona S. Rowe

    Enter the experimental floor of the National Synchrotron Light Source II (NSLS-II) and you’ll find an obstacle course. Around and across the half-mile circular floor are hutches jutting out for the NSLS-II “project” beamlines, cage after cage housing workbenches and tools, and parts along the inner and outer perimeters waiting for installation. Now come the three ABBIX beamlines.

    Brookhaven NSLS II Photo
    NSLS II

    “It’s full speed ahead for ABBIX,” said project manager Lonny Berman, physicist with the Photon Sciences Directorate.

    team
    ABBIX team

    ABBIX is an acronym for Advanced Beamlines for Biological Investigations with X-rays. The National Institutes of Health (NIH) is supporting the construction of these beamlines with $45 million, supplemented by $3 million from the NSLS-II construction budget, money that came from the Department of Energy (DOE).

    Some recent and projected dates: ABBIX was baselined in April 2013, which set the budget and schedule. The final design report was approved in November 2013. Now is a period of procurement and installation of accelerator and beamline components. According to Berman, early project completion is expected by the end of calendar year 2015, with project closeout scheduled for June 2016.

    ABBIX consists of three beamlines:

    AMX (Flexible Access and Automated Macromolecular Crystallography)
    FMX (Frontier Macromolecular Crystallography)
    LiX (High-brightness X-ray Scattering for Life Sciences)

    Dieter Schneider, beamline group leader for both AMX and FMX, explained that the new crystallography beamlines will provide structural biologists with a pair of uniquely powerful beamlines for the efficient structure determination and functional studies of biomedically important macromolecules ranging in complexity from enzymes to large molecular assemblies with organelle-like functions.

    “Particularly valuable will be FMX’s micron-sized beams for wringing structures from large numbers of even the smallest crystals of membrane proteins, notorious for their fragility and heterogeneity when grown large,” said Schneider. “AMX – with a very high flux, short data collection times of just seconds, and automated specimen handling – will make it easy to measure each crystal in a lot of many crystals to obtain high data quality from relational sorting of redundant experiments.” He added that to better connect an investigator’s crystallization lab with NSLS-II and shorten the biochemistry-to-structure process, AMX and FMX will be able to characterize arrays of crystallization trials by diffraction at room temperature.

    The LiX beamline is designed to be a versatile instrument capable of multiple modes of operations all dedicated to life science applications, according to Lin Yang, group leader for that beamline. He said, “Compared to existing facilities, LiX will allow researchers to study the structures of biological molecules in their near-native environments much more quickly and at improved time resolution. The beamline’s wide energy range also presents unique opportunities to solve novel membrane structures.”

    In addition, Yang noted, researchers can examine the structures of biological tissues using scanning-probe imaging. And although the beamline has to accommodate different types of experiments, “the modular design of the experimental station enables rapid switching between experiments to maximize the utility of the beam time,” said Yang.

    Located at roughly 10 o’clock on the NSLS-II circle, the ABBIX beamlines are clustered in two (out of 30) wedges of the experimental floor and labeled 16-ID and 17-ID. (“ID” stands for insertion device, a special multi-magnet device that is “inserted” into a straight arm of the polygonal NSLS-II synchrotron ring to increase the brilliance of the x-ray beam delivered to the beamline.)

    Construction of the hutches for LiX started in December 2013, with New Jersey-based Global Partners in Shielding (GPS) assembling steel enclosures in which experiments will be done. That work was substantially completed in March 2014. Now, GPS and the French company Caratelli have started building the steel and lead hutches, respectively, for AMX and FMX.

    This activity is taking place along the inside edge of lab-office building 5 (Bldg. 745), where the ABBIX offices are located. Sharing space with the NSLS Macromolecular Crystallography Research Resource, known by the acronym PXRR and supported by NIH and by DOE’s Office of Biological and Environmental Research (BER), and the East Coast Structural Biology Research group, supported by NIH’s National Institute of General Medical Sciences, the ABBIX project is fully integrated in the structural biology program of NSLS-II that is operating beamlines at NSLS until the end of September 2014, when NSLS will shut down.

    “These two groups, plus ABBIX and members of the staff of the SRX [NSLS-II] project beamline, have teamed up to request further funding in a joint grant from NIH and DOE BER for the future operation of these and other life-science beamlines at NSLS-II,” said Bob Sweet, structural biologist in Photon Sciences. Sweet is principal investigator for PXRR and is leading the effort to win the new NIH/DOE grant. “The three ABBIX beamlines will be the first devoted to life sciences at NSLS-II,” he said, adding that several NSLS-II project beamlines have the capability to do some types of imaging and may host the first life science experiments performed at the new facility in the coming year.

    In the years leading up to NSLS-II construction, NIH evaluated the needs of the life sciences user community, with input from special advisory panels. ABBIX beamlines will address the needs of this community by providing small intense beams to improve sensitivity of crystal structure determination, critical for tiny crystals of proteins that are difficult to crystallize, particularly membrane proteins. And using such small beams, scientists will also gain unique insight into questions about the structure and behavior of macromolecules and macromolecular assemblies in solution, at time scales as short as 10 microseconds.

    See the full article here.

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 3:02 pm on March 27, 2014 Permalink | Reply
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    From SLAC Lab- “Science with Bling: Turning Graphite into Diamond” 

    March 27, 2014
    Manuel Gnida

    A research team led by SLAC scientists has uncovered a potential new route to produce thin diamond films for a variety of industrial applications, from cutting tools to electronic devices to electrochemical sensors.

    lead
    SLAC researchers have found a new way to transform graphite — a pure form of carbon most familiar as the lead in pencils — into a diamond-like film. (Fabricio Sousa/SLAC)

    lattice
    This illustration shows four layers of transformed graphene (single sheets of graphite, with carbon atoms represented as black spheres) on a platinum surface (blue spheres). The addition of hydrogen atoms (green spheres) to the top layer has set off a domino effect that transformed this graphite-like material into a diamond-like film. The film is stabilized by bonds between the platinum substrate and the bottom-most carbon layer. (Sarp Kaya and Frank Abild-Pedersen/SUNCAT)

    The scientists added a few layers of graphene – one-atom thick sheets of graphite – to a metal support and exposed the topmost layer to hydrogen. To their surprise, the reaction at the surface set off a domino effect that altered the structure of all the graphene layers from graphite-like to diamond-like.

    “We provide the first experimental evidence that hydrogenation can induce such a transition in graphene,” says Sarp Kaya, researcher at the SUNCAT Center for Interface Science and Catalysis and corresponding author of the recent study.

    From Pencil Lead to Diamond

    Graphite and diamond are two forms of the same chemical element, carbon. Yet, their properties could not be any more different. In graphite, carbon atoms are arranged in planar sheets that can easily glide against each other. This structure makes the material very soft and it can be used in products such as pencil lead.

    In diamond, on the other hand, the carbon atoms are strongly bonded in all directions; thus diamond is extremely hard. Besides mechanical strength, its extraordinary electrical, optical and chemical properties contribute to diamond’s great value for industrial applications.

    Scientists want to understand and control the structural transition between different carbon forms in order to selectively transform one into another. One way to turn graphite into diamond is by applying pressure. However, since graphite is the most stable form of carbon under normal conditions, it takes approximately 150,000 times the atmospheric pressure at the Earth’s surface to do so.

    Now, an alternative way that works on the nanoscale is within grasp. “Our study shows that hydrogenation of graphene could be a new route to synthesize ultrathin diamond-like films without applying pressure,” Kaya says.

    Domino Effect

    For their experiments, the researchers loaded a platinum support with up to four sheets of graphene and added hydrogen to the topmost layer. With the help of intense X-rays from SLAC’s Stanford Synchrotron Radiation Lightsource (SSRL, Beam Line 13-2) and additional theoretical calculations performed by SUNCAT researcher Frank Abild-Pedersen, the team then determined how hydrogen impacted the layered structure.

    SLAC SSRL
    Inside SSRL

    They found that hydrogen binding initiated a domino effect, with structural changes propagating from the sample’s surface through all the carbon layers underneath, turning the initial graphite-like structure of planar carbon sheets into an arrangement of carbon atoms that resembles diamond.

    The discovery was unexpected. The original goal of the experiment was to see if adding hydrogen could alter graphene’s properties in a way that would make it useable in transistors, the fundamental building block of electronic devices. Instead, the scientists discovered that hydrogen binding resulted in the formation of chemical bonds between graphene and the platinum substrate.

    It turns out that these bonds are crucial for the domino effect. “For this process to be stable, the platinum substrate needs to bond to the carbon layer closest to it,” Kaya explains. “Platinum’s ability to form these bonds determines the overall stability of the diamond-like film.”

    Future research will explore the full potential of hydrogenated few-layer graphene for applications in the material sciences. It will be particularly interesting to determine if diamond-like films can be grown on other metal substrates, using graphene of various thicknesses.

    The research team included scientists from Stanford University, the Stanford Institute for Materials & Energy Sciences (SIMES), SUNCAT and SSRL.

    See the full article here.

    SLAC Campus
    SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the DOE’s Office of Science.
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  • richardmitnick 5:23 am on March 27, 2014 Permalink | Reply
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    From Brookhaven Lab: “Scientists Track 3D Nanoscale Changes in Rechargeable Battery Material During Operation” 

    Brookhaven Lab

    March 26, 2014
    Contacts: Karen McNulty Walsh, (631) 344-8350 or Peter Genzer, (631) 344-3174

    First 3D nanoscale observations of microstructural degradation during charge-discharge cycles could point to new ways to engineer battery electrode materials for better performance.

    Scientists at the U.S. Department of Energy’s Brookhaven National Laboratory have made the first 3D observations of how the structure of a lithium-ion battery anode evolves at the nanoscale in a real battery cell as it discharges and recharges. The details of this research, described in a paper published in Angewandte Chemie, could point to new ways to engineer battery materials to increase the capacity and lifetime of rechargeable batteries.

    “For the first time, we have captured the microstructural details of an operating battery anode in 3D with nanoscale resolution.”
    — Brookhaven physicist Jun Wang

    “This work offers a direct way to look inside the electrochemical reaction of batteries at the nanoscale to better understand the mechanism of structural degradation that occurs during a battery’s charge/discharge cycles,” said Brookhaven physicist Jun Wang, who led the research. “These findings can be used to guide the engineering and processing of advanced electrode materials and improve theoretical simulations with accurate 3D parameters.”

    Chemical reactions in which lithium ions move from a negatively charged electrode to a positive one are what carry electric current from a lithium-ion battery to power devices such as laptops and cell phones. When an external current is applied—say, by plugging the device into an outlet—the reaction runs in reverse to recharge the battery.

    depict
    The top row shows how tin particles evolve in three dimensions during the first two lithiation–delithiation cycles in the model lithium-ion rechargeable battery cell. The bottom row shows “cross-sectional” images of a single tin particle during the first two cycles. Severe fracture and pulverization occur during the initial stage of cycling. The particle stays mechanically stable after the first cycle, while the electrochemical reaction proceeds reversibly.

    Scientists have long known that repeated charging/discharging (lithiation and delithiation) introduces microstructural changes in the electrode material, particularly in some high-capacity silicon and tin-based anode materials. These microstructural changes reduce the battery’s capacity—the energy the battery can store—and its cycle life—how many times the battery can be recharged over its lifetime. Understanding in detail how and when in the process the damage occurs could point to ways to avoid or minimize it.

    “It has been very challenging to directly visualize the microstructural evolution and chemical composition distribution changes in 3D within electrodes when a real battery cell is going through charge and discharge,” said Wang.

    A team led by Vanessa Wood of the university ETH Zurich, working at the Swiss Light Source, recently performed in situ 3D tomography at micrometer scale resolution during battery cell charge and discharge cycles.

    Achieving nanoscale resolution has been the ultimate goal.

    “For the first time,” said Wang, “we have captured the microstructural details of an operating battery anode in 3D with nanoscale resolution, using a new in-situ micro-battery-cell we developed for synchrotron x-ray nano-tomography—an invaluable tool for reaching this goal.” This advance provides a powerful new source of insight into microstructural degradation.
    Building a micro battery

    Developing a working micro battery cell for nanoscale x-ray 3D imaging was very challenging. Common coin-cell batteries aren’t small enough, plus they block the x-ray beam when it is rotated.

    “The whole micro cell has to be less than one millimeter in size but with all battery components—the electrode being studied, a liquid electrolyte, and the counter electrode—supported by relatively transparent materials to allow transmission of the x-rays, and properly sealed to ensure that the cell can work normally and be stable for repeated cycling,” Wang said. The paper explains in detail how Wang’s team built a fully functioning battery cell with all three battery components contained within a quartz capillary measuring one millimeter in diameter.

    By placing the cell in the path of high-intensity x-ray beams generated at beamline X8C of Brookhaven’s National Synchrotron Light Source (NSLS), the scientists produced more than 1400 two-dimensional x-ray images of the anode material with a resolution of approximately 30 nanometers. These 2D images were later reconstructed into 3D images, much like a medical CT scan but with nanometer-scale clarity. Because the x-rays pass through the material without destroying it, the scientists were able to capture and reconstruct how the material changed over time as the cell discharged and recharged, cycle after cycle.

    Brookhaven NSLS
    Brookhaven NSLS

    images
    These images show how the surface morphology and internal microstructure of an individual tin particle changes from the fresh state through the initial lithiation and delithiation cycle (charge/discharge). Most notable are the expansion in overall particle volume during lithiation, and reduction in volume and pulverization during delithiation. The cross-sectional images reveal that delithiation is incomplete, with the core of the particle retaining lithium surround by a layer of pure tin.

    Using this method, the scientists revealed that, “severe microstructural changes occur during the first delithiation and subsequent second lithiation, after which the particles reach structural equilibrium with no further significant morphological changes.”

    Specifically, the particles making up the tin-based anode developed significant curvatures during the early charge/discharge cycles leading to high stress. “We propose that this high stress led to fracture and pulverization of the anode material during the first delithiation,” Wang said. Additional concave features after the first delithiation further induced structural instability in the second lithiation, but no significant changes developed after that point.

    “After these initial two cycles, the tin anode shows a stable discharge capacity and reversibility,” Wang said.

    “Our results suggest that the substantial microstructural changes in the electrodes during the initial electrochemical cycle—called forming in the energy storage industry—are a critical factor affecting how a battery retains much of its current capacity after it is formed,” she said. “Typically a battery loses a substantial portion of its capacity during this initial forming process. Our study will improve understanding of how this happens and help us develop better controls of the forming process with the goal of improving the performance of energy storage devices.”

    three
    Jiajun Wang, Karen Chen and Jun Wang prepare a sample for study at NSLS beamline X8C.

    Wang pointed out that while the current study looked specifically at a battery with tin as the anode, the electrochemical cell her team developed and the x-ray nanotomography technique can be applied to studies of other anode and cathode materials. The general methodology for monitoring structural changes in three dimensions as materials operate also launches an opportunity to monitor chemical states and phase transformations in catalysts, other types of materials for energy storage, and biological molecules.

    The transmission x-ray microscope used for this study will soon move to a full-field x-ray imaging (FXI) beamline at NSLS-II, a world-class synchrotron facility now nearing completion at Brookhaven Lab. This new facility will produce x-ray beams 10,000 times brighter than those at NSLS, enabling dynamic studies of various materials as they perform their particular functions.

    Jiajun Wang and Yu-chen Karen Chen-Wiegart are research associates in Wang’s research group and performed the work together.

    This research was funded as a Laboratory Directed Research and Development project at Brookhaven Lab and by the DOE Office of Science. The transmission x-ray microscope used in this work was built with funding from the American Recovery and Reinvestment Act.

    DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

    See the full article here.

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 3:30 pm on March 25, 2014 Permalink | Reply
    Tags: , , , , , X-ray Technology   

    From SLAC Lab: “A New Way to Tune X-ray Laser Pulses” 

    [New policies at SLAC are resulting in my bringing the lab's news later than necessary. SLAC is working on improving the situation.]

    March 10, 2014
    Glenn Roberts Jr.

    A new system at SLAC National Accelerator Laboratory’s X-ray laser narrows a rainbow spectrum of X-ray colors to a more intense band of light, creating a much more powerful way to view fine details in samples at the scale of atoms and molecules.

    “It’s like going from regular television to HDTV,” said Norbert Holtkamp, SLAC deputy director and leader of the lab’s Accelerator Directorate.

    Designed and installed at SLAC’s Linac Coherent Light Source (LCLS) in collaboration with Lawrence Berkeley National Laboratory and Switzerland’s Paul Scherrer Institute, it is the world’s first “self-seeding” system for enhancing lower-energy or “soft” X-rays.

    Scientists had to overcome a series of engineering challenges to build it, and it is already drawing international interest for its potential use at other X-ray free-electron lasers.

    “Because this system delivers more intense soft X-ray light at the precise energy we want for experiments, we can make measurements at a far faster rate,” said Bill Schlotter, an LCLS staff scientist. “It will open new possibilities, from exploring exotic materials and biological and chemical samples in greater detail to improving our view of the behavior of atoms and molecules.”

    Cutting Through the Noise

    LCLS’s laser pulses vary in intensity and color, and this randomness or “noise,” like fuzzy reception on a TV, sometimes complicates experiments and data analysis. Self-seeding cuts through this noise by providing a stronger and more consistent intensity peak within each laser pulse.

    “We’re taking something that’s in a range of colors and trying to select a single color and pack as much power in as we can,” said Daniel Ratner, an associate staff scientist at SLAC and lead scientist on the project. “We’re going from the randomness of a typical pulse to a nice, clean, narrow profile that is well-understood.”

    Scientists had installed another self-seeding system at LCLS in 2012 for higher-energy “hard” X-rays. It has been put to use in studies of matter under extreme temperatures and pressures, the structure of biological molecules and electron motions in materials, for example.

    Extending self-seeding to soft X-rays was a logical next step. LCLS scientists Yiping Feng, Daniele Cocco and others designed a compact X-ray optics system that was key to the success of the project, which was led by SLAC’s Jerry Hastings and Zhirong Huang.

    The team achieved self-seeding with soft X-rays in December, and conducted follow-up tests in January and February. They are working to improve the system and to make it available to visiting scientists.

    LCLS X-ray pulses are powered by an electron beam from SLAC’s linear accelerator. The electrons wiggle through a series of powerful magnets, called undulators. This forces them to emit X-ray light, and that light grows in intensity as it moves through the undulator chain.

    SLAC Linear Accelerator
    SLAC Linear Accelerator

    The new system, installed about a quarter of the way down the undulator chain, diverts a narrow, purified slice of the X-ray laser light and briefly and precisely overlaps it with the beam of electrons traveling through the undulators. This produces a “seed” – a spike of high-intensity light in a single color – that is amplified as the X-ray pulses move through the remaining undulators toward LCLS experimental stations.

    Engineering Challenge

    “A big technical challenge was to fit everything in one 13-foot-long undulator section,” including a complex network of cabling, optics, magnets and mechanical systems, said SLAC’s Paul Montanez, project manager and lead engineer for the system. “A tremendous number of people pulled this project together, from administrative, technical and professional staff to scientists.”

    feeder
    A view of the soft X-ray self-seeding system during installation in the Undulator Hall at SLAC’s Linac Coherent Light Source X-ray laser. (Brad Plummer/SLAC)

    man
    Ziga Oven monitors the installation of the soft X-ray self-seeding system in the Undulator Hall at SLAC’s Linac Coherent Light Source X-ray laser. (Brad Plummer/SLAC)

    The Berkeley Lab team designed and built the hardware that diverts and refines the X-ray light, as well as mechanical systems that align the X-rays and electrons, adjust the X-ray energy and retract components out of the path of X-rays when not in use. The Paul Scherrer team designed and built the optical equipment for the system. SLAC was responsible for integrating the components and building the controls that automate the system.

    “This project was pretty challenging in that we were designing and developing and installing this equipment in an operating facility, with little time for the actual installation,” said Ken Chow, the lead engineer for the Berkeley Lab effort. He noted that the project required many custom parts, such as a movable mirror that must rotate with incredible precision – “It’s like taking a meter stick and moving one end one-half millionth of a meter,” he said.

    Next Steps

    SLAC scientists are hoping to use the seeding system, coupled with an intricate tuning of the magnets in the undulators, to produce even higher-intensity pulses for the next generation of X-ray lasers.

    Already, collaborators from the Paul Scherrer Institute are considering a similar self-seeding system for a planned soft X-ray laser in Switzerland, and there has been great interest in such a system for other X-ray laser projects in the works.

    “We would like to learn and profit from this for our own project, the SwissFEL,” said Uwe Flechsig, who led the Paul Scherrer team that was responsible for delivering the system’s optics.

    See the full article here.

    SLAC Campus
    SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the DOE’s Office of Science.
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  • richardmitnick 4:16 pm on March 21, 2014 Permalink | Reply
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    From Argonne APS: “A Layered Nanostructure Held Together By DNA” 

    News from Argonne National Laboratory

    March 18, 2014
    David Lindley

    Dreaming up nanostructures that have desirable optical, electronic, or magnetic properties is one thing. Figuring out how to make them is another. A new strategy uses the binding properties of complementary strands of DNA to attach nanoparticles to each other and builds up a layered thin-film nanostructure through a series of controlled steps. Investigation at the U.S. Department of Energy Office of Science’s Advanced Photon Source has revealed the precise form that the structures adopted, and points to ways of exercising still greater control over the final arrangement.

    dna
    DNA

    The idea of using DNA to hold nanoparticles was devised more than 15 years ago by Chad Mirkin and his research team at Northwestern University. They attached short lengths of single-stranded DNA with a given sequence to some nanoparticles, and then attached DNA with the complementary sequence to others. When the particles were allowed to mix, the “sticky ends” of the DNA hooked up with each other, allowing for reversible aggregation and disaggregation depending on the hybridization properties of the DNA linkers.

    sticky
    Nanoparticles linked by complementary DNA strands form a bcc superlattice when added layer-by-layer to a DNA coated substrate. When the substrate DNA is all one type, the superlattice forms at a different orientation (top row) than if the substrate has both DNA linkers (bottom row). GISAXS scattering patterns (right) and scanning electron micrographs (inset) reveal the superlattice structure. No image credit.

    Recently, this DNA “smart glue” has been utilized to assemble nanoparticles into ordered arrangements resembling atomic crystal lattices, but on a larger scale. To date, nanoparticle superlattices have been synthesized in well over 100 crystal forms, including some that have never been observed in nature.

    However, these superlattices are typically polycrystalline, and the size, number, and orientation of the crystals within them is generally unpredictable. To be useful as metamaterials, photonic crystals, and the like, single superlattices with consistent size and fixed orientation are needed.

    Northwestern researchers and a colleague at Argonne National Laboratory have devised a variation on the DNA-linking procedure that allows a greater degree of control.

    The basic elements of the superlattice were gold nanoparticles, each 10 nanometers across. These particles were made in two distinct varieties, one adorned with approximately 60 DNA strands of a certain sequence, while the other carried the complementary sequence.

    The researchers built up thin-film superlattices on a silicon substrate that was also coated with DNA strands. In one set of experiments, the substrate DNA was all of one sequence – call it the “B” sequence – and it was first dipped into a suspension of nanoparticles with the complementary “A” sequence.

    When the A and B ends connected, the nanoparticles formed a single layer on the substrate. Then the process was repeated with a suspension of the B-type nanoparticles, to form a second layer. The whole cycle was repeated, as many as four more times, to create a multilayer nanoparticle superlattice in the form of a thin film.

    Grazing incidence small-angle x-ray scattering (GISAXS) studies carried out at the X-ray Science Division 12-ID-B beamline at the Argonne Advanced Photon Source revealed the symmetry and orientation of the superlattices as they formed. Even after just three half-cycles, the team found that the nanoparticles had arranged themselves into a well-defined, body-centered cubic (bcc) structure, which was maintained as more layers were added.

    In a second series of experiments, the researchers seeded the substrate with a mix of both the A and B types of DNA strand. Successive exposure to the two nanoparticle types produced the same bcc superlattice, but with a different vertical orientation. That is, in the first case, the substrate lay on a plane through the lattice containing only one type of nanoparticle, while in the second case, the plane contained an alternating pattern of both types (see the figure).

    To get orderly superlattice growth, the researchers had to conduct the process at the right temperature. Too cold, and the nanoparticles would stick to the substrate in an irregular fashion, and remain stuck. Too hot, and the DNA linkages would not hold together.

    But in a temperature range of a couple of degrees on either side of about 40° C (just below the temperature at which the DNA sticky ends detach from each other), the nanoparticles were able to continuously link and unlink from each other. Over a period of about an hour per half-cycle, they settled into the bcc superlattice, the most thermodynamically stable arrangement.

    GISAXS also revealed that although the substrate forced superlattices into specific vertical alignments, it allowed the nanoparticle crystals to form in any horizontal orientation. The researchers are now exploring the possibility that by patterning the substrate in a suitable way, they can control the orientation of the crystals in both dimensions, increasing the practical value of the technique.

    See the full article here.

    Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science

    The Advanced Photon Source at Argonne National Laboratory is one of five national synchrotron radiation light sources supported by the U.S. Department of Energy’s Office of Science to carry out applied and basic research to understand, predict, and ultimately control matter and energy at the electronic, atomic, and molecular levels, provide the foundations for new energy technologies, and support DOE missions in energy, environment, and national security.

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  • richardmitnick 3:47 pm on March 21, 2014 Permalink | Reply
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    From Brookhaven Lab: “Understanding the Initiation of Protein Synthesis in Mammals” 

    Brookhaven Lab

    March 18, 2014
    Chelsea Whyte

    Protein synthesis, the process by which cells generate new proteins, is the most important cellular function, requiring more than 70 percent of the total energy of a cell. The initiation of this process is the most regulated and most critical component, but it is still the least understood.

    protein
    Messenger RNA (in red) latches closed around a pre-initiation complex, and attaches to transfer RNA (in green), beginning a process of protein synthesis specific to eukaryotes — animals, plants, and fungi.

    Research by Ivan Lomakin and Thomas Steitz of Yale University has unlocked the genetic scanning mechanism that begins this crucial piece of cell machinery.

    They determined the structures of three complexes of the ribosome, a complex molecular machine that links together amino acids to form proteins according to an order specified by messenger RNA. These three structures represent distinct steps in protein translation in mammals – the recruitment and scanning of mRNA, the selection of initiator tRNA, and the joining of large and small ribosomal subunits.

    “Any small defect or disruption in the protein synthesis process can cause abnormalities or disease,” said Lomakin. “Understanding this process is critical for understanding how human life comes to be, and how some over-expressions or abnormalities in the initiation of protein synthesis may be connected to cancer or Alzheimer’s or other diseases.”

    Using x-ray crystallography on ribosomal subunits purified from rabbit cells, they were able to determine the positions and roles of the different pieces of cellular machinery, a bit like creating a playbook for a football game. They found that the tRNA and mRNA compete for position at the P site – one of three key sites on a ribosome – where short chains of amino acids are linked to form proteins.

    “Now, we have a low resolution structure, so we can’t yet talk about atomic details of the mechanism,” said Lomakin. “The next important step is to get higher resolution images. And we can change organisms to see if they behave differently, so we’re working on the structure of human ribosome initiation complexes, too.”

    For this higher resolution, Lomakin and his collaborators will use the National Synchrotron Light Source II, a new state-of-the-art light source that will begin early science at Brookhaven National Laboratory in 2014. “Our hope is to be able to look at very weak diffraction to get higher resolution structures of these important cellular mechanisms.”

    Brookhaven NSLS II Photo
    NSLS-II at Brookhaven Lab

    See the full article here.

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 12:53 pm on March 20, 2014 Permalink | Reply
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    From SLAC Lab: “Scientists Discover Potential Way to Make Graphene Superconducting” 

    March 20, 2014
    Press Office Contact:
    Andy Freeberg, afreeberg@slac.stanford.edu, (650) 926-4359

    Scientist Contact:
    Shuolong Yang, syang2@stanford.edu, (650) 725-0440

    Scientists at the Department of Energy’s SLAC National Accelerator Laboratory and Stanford University have discovered a potential way to make graphene – a single layer of carbon atoms with great promise for future electronics – superconducting, a state in which it would carry electricity with 100 percent efficiency.

    graph

    Researchers used a beam of intense ultraviolet light to look deep into the electronic structure of a material made of alternating layers of graphene and calcium. While it’s been known for nearly a decade that this combined material is superconducting, the new study offers the first compelling evidence that the graphene layers are instrumental in this process, a discovery that could transform the engineering of materials for nanoscale electronic devices.

    “Our work points to a pathway to make graphene superconducting – something the scientific community has dreamed about for a long time, but failed to achieve,” said Shuolong Yang, a graduate student at the Stanford Institute of Materials and Energy Sciences (SIMES) who led the research at SLAC’s Stanford Synchrotron Radiation Lightsource (SSRL).

    ssrl
    Stanford University / SLAC professor Zhi Xun Shen with a spectrometer at Stanford Synchrotron Radiation Lightsource (SSRL) Beamline 5-4.

    The researchers saw how electrons scatter back and forth between graphene and calcium, interact with natural vibrations in the material’s atomic structure and pair up to conduct electricity without resistance. They reported their findings March 20 in Nature Communications.

    Graphite Meets Calcium

    Graphene, a single layer of carbon atoms arranged in a honeycomb pattern, is the thinnest and strongest known material and a great conductor of electricity, among other remarkable properties. Scientists hope to eventually use it to make very fast transistors, sensors and even transparent electrodes.

    The classic way to make graphene is by peeling atomically thin sheets from a block of graphite, a form of pure carbon that’s familiar as the lead in pencils. But scientists can also isolate these carbon sheets by chemically interweaving graphite with crystals of pure calcium. The result, known as calcium intercalated graphite or CaC6, consists of alternating one-atom-thick layers of graphene and calcium.

    The discovery that CaC6 is superconducting set off a wave of excitement: Did this mean graphene could add superconductivity to its list of accomplishments? But in nearly a decade of trying, researchers were unable to tell whether CaC6’s superconductivity came from the calcium layer, the graphene layer or both.

    Observing Superconducting Electrons

    For this study, samples of CaC6 were made at University College London and brought to SSRL for analysis.

    “These are extremely difficult experiments,” said Patrick Kirchmann, a staff scientist at SLAC and SIMES. But the purity of the sample combined with the high quality of the ultraviolet light beam allowed them to see deep into the material and distinguish what the electrons in each layer were doing, he said, revealing details of their behavior that had not been seen before.

    “With this technique, we can show for the first time how the electrons living on the graphene planes actually superconduct,” said SIMES graduate student Jonathan Sobota, who carried out the experiments with Yang. “The calcium layer also makes crucial contributions. Finally we think we understand the superconducting mechanism in this material.”

    Although applications of superconducting graphene are speculative and far in the future, the scientists said, they could include ultra-high frequency analog transistors, nanoscale sensors and electromechanical devices and quantum computing devices.

    The research team was supervised by Zhi-Xun Shen, a professor at SLAC and Stanford and SLAC’s advisor for science and technology, and included other researchers from SLAC, Stanford, Lawrence Berkeley National Laboratory and University College London. The work was supported by the DOE’s Office of Science, the Engineering and Physical Sciences Research Council of UK and the Stanford Graduate Fellowship program.

    SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, Calif., SLAC is operated by Stanford University for the U.S. Department of Energy’s Office of Science.

    The Stanford Institute for Materials and Energy Sciences (SIMES) is a joint institute of SLAC National Accelerator Laboratory and Stanford University. SIMES studies the nature, properties and synthesis of complex and novel materials in the effort to create clean, renewable energy technologies. For more information, visit simes.slac.stanford.edu.

    SLAC’s Stanford Synchrotron Radiation Lightsource (SSRL) is a third-generation light source producing extremely bright X-rays for basic and applied science. A DOE national user facility, SSRL attracts and supports scientists from around the world who use its state-of-the-art capabilities to make discoveries that benefit society. For more information, visit ssrl.slac.stanford.edu.

    DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, visit science.energy.gov.

    See the full article here.

    SLAC Campus
    SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the DOE’s Office of Science.
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  • richardmitnick 2:34 pm on March 11, 2014 Permalink | Reply
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    From SLAC: “X-ray Laser Sheds New Light on Quest for Faster Data Storage” 

    March 6, 2014
    Glenn Roberts Jr.

    An experiment at SLAC’s X-ray laser has revealed the first atomic-scale details of a new technique that could point the way to faster data storage in smartphones, laptops and other devices.

    Researchers used pulses of specially tuned light to change the magnetic properties of a material with potential for data storage. Then they used SLAC’s Linac Coherent Light Source (LCLS) X-ray laser to directly measure those magnetic changes – and discovered that they took place in less than 1 trillionth of a second, about a billion times faster than previously observed in similar materials.

    SLAC LCLS Inside
    SLAC LCLS inside

    “This is much shorter than the previously established limit of several thousandths of a second in this type of material, and suggests a possible new approach for memory devices,” said Teresa Kubacka, a doctoral researcher at the Swiss Federal Institute of Technology in Zurich and lead author of the study.

    What’s more, she said, the new method may be more efficient than current techniques for magnetic data storage.

    The team, which included scientists from the Paul Scherrer Institute, SLAC, the Stanford Institute for Materials and Energy Sciences (SIMES) and other research centers, described its findings in the March 6 issue of Science.

    Commercially available magnetic data storage devices use magnetic heads to switch domains on a moving medium in billionths of a second. These domains, read as ones and zeroes, are the building blocks of computer data.

    The material in this study, called terbium manganite, was selected because it is “multiferroic” – it has both magnetic and electrical properties, which are coupled in a way that allows a unique form of magnetic switching driven by an electric field. This makes it a good model for developing similar materials with more commercial promise.

    In the experiment, researchers tuned an optical laser to produce light at a specific frequency that electrically excited the material and triggered magnetic changes while minimizing any heating effects. These excitations, known as “electromagnons,” may offer a way to drastically speed up a material’s magnetic response to electric pulses.

    Then the researchers used the LCLS X-ray laser to make the first direct observation of the magnetic response to the electric pulses. They discovered that the spins of the electrons in the material – which are like tiny, atomic-scale magnets – began to move toward a switched magnetic state in just a trillionth of a second, although they stopped short of completing the switch.

    While previous studies have used laser pulses to switch the magnetic states of purely magnetic materials, those methods were less direct and less efficient. And in multiferroics, other approaches that are based on simply turning the electric field on and off lead to changes about a million times slower than in today’s commercial devices.

    Many advances are needed to make the new approach viable, Kubacka noted. In the LCLS experiment, for example, the material was cooled with liquid helium in order to align its magnetic and electrical properties and a large laser system was required to produce the electric field pulse.

    To build a commercially viable device, it may be possible to amplify light from a smaller laser or identify another mechanism for producing an electric field pulse strong enough to manipulate magnetism and achieve full switching of magnetic domains, she said. Other materials that exhibit the desired magnetic and electric coupling are also being sought.

    “The big challenge in the field is to find a similar room-temperature material with a relatively simple structure so that it could be suitable for commercial applications,” Kubacka said.

    Researchers from Lawrence Berkeley National Laboratory and Johns Hopkins University also participated in the experiment.This research was carried out on the Soft X-ray Materials Science experimental station, which is funded by a consortium including LCLS, Stanford, Berkeley Lab, the University of Hamburg and the Center for Free Electron Laser Science. The research was also supported by the Swiss National Science Foundation and the Department of Energy Office of Science.

    sxr
    SXR in action

    SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the U.S. Department of Energy Office of Science. To learn more, please visit http://www.slac.stanford.edu.

    SLAC’s LCLS is the world’s most powerful X-ray free-electron laser. A DOE Office of Science national user facility, its highly focused beam shines a billion times brighter than previous X-ray sources to shed light on fundamental processes of chemistry, materials and energy science, technology and life itself. For more information, visit lcls.slac.stanford.edu.

    See the full article here.

    SLAC Campus
    SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the DOE’s Office of Science.
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  • richardmitnick 5:24 pm on March 5, 2014 Permalink | Reply
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    From ARGONNE APS: “Squeezing Out the Hidden Lives of Electrons” 

    News from Argonne National Laboratory

    FEBRUARY 26, 2014
    Jenny Morber

    In our daily lives we tend to think of electrical conductivity as largely static: Copper is a good choice for conduction; clay is not. But heat up that copper wire, and electron conduction slows. Give a flake of that ceramic a good squeeze, and conduction may perk up. Conductivity is determined by much more than simple chemistry. Metal-to-insulator transitions have excited and perplexed researchers for over a century, and they continue to provide fodder for research today. The key to understanding what causes changes in material conductivity lies in teasing out contributions from structural atomic arrangements and electron interactions. Researchers using high-energy x-rays from the U.S. Department of Energy Office of Science’s Advanced Photon Source (APS) have managed to disentangle these components in vanadium sesquioxide (V2O3), an extensively studied model solid. By decoupling the effects of spin, charge, and lattice variables in V2O3, the team is uncovering a mechanism that has eluded researchers for six decades.

    graph
    Electrical resistance as a function of pressure in V2O3. As pressure increases from 5 GPa, resistance decreases as expected. At 12.5 GPa the sharp increase in resistance is an unexpected result of electron-lattice interactions. At ~33 GPa, the material’s corundum hexagonal structure changes to monoclinic, and resistance rises more sharply due to electron-electron interactions. Here the material is on the cusp of a metal-to-insulator transition.

    With measurements performed at the LERIX instrument at X-ray Science Division (XSD) beamline 20-ID and the High Pressure Collaborative Access Team (HP-CAT) beamline 16-ID, both at the APS, and calculations from the XSD Theory Group, the researchers have identified a structural phase change in V2O3 that occurs under great pressure, but without the usual metal-to-insulator transition. The interplay between crystal structure and electronic properties underlies almost every modern device, from pressure sensors to superconducting high speed trains.

    Under normal conditions, V2O3 is a black metallic solid with a corundum crystal structure, like that of rubies and sapphires. With changes in temperature it undergoes spectacular metal-to-insulator transitions, often with changes in magnetic behavior as well. These unusual properties make V2O3 a material of choice in devices that include temperature sensors and current regulators.

    Researchers had previously reported interesting behavior in V2O3 as temperature changed and pressure remained constant. Here the team tested the opposite condition, monitoring the material’s resistance while increasing the pressure at a constant temperature.

    At first everything seemed normal—as the pressure increased the material’s resistance also decreased. But around 12.5 GPa the resistance began to rise. This result was unexpected. Even more unusual, at greater pressures near 33 GPa, the material’s structure changed from corundum to a more compact monoclinic arrangement of atoms, but this change was not accompanied by a corresponding spike in resistance (see the figure). The material remained metallic. Previously, all corundum to monoclinic changes in structure had been accompanied by a simultaneous transition from metallic to insulating behavior.

    To understand what was happening, the researchers performed inelastic x-ray scattering measurements and compared the results with theoretical simulations. Because inelastic x-ray spectroscopy measures the unoccupied vanadium electron valence states, these measurements provide a more detailed picture of electron screening interactions.

    While the resistivity measurements clearly showed changes at 12.5 GPa, the inelastic x-ray spectra showed no differences up to the phase change pressure of 33 GPa. This means that the early changes in resistance were due not to changes in electron correlations, but to interactions between electrons and the lattice (or phonons).

    At high pressure the electronic structure changed drastically in the inelastic x-ray spectra, suggesting an increase in electron correlations, but not quite enough to tip the material into the category of an insulator. At such high pressure, V2O3 is on the verge of becoming an insulator, but can’t quite make the change due to competing effects from the lattice.

    This work adds another clue to our understanding of how long-range atomic arrangement and local electron interactions work competitively to manifest metal-to-insulator transitions in solids.

    The next step will be to explore electron correlations in V2O3 by using more advanced techniques, such as the resonant x-ray inelastic scattering method with temperature, as another parameter to extend the unique phase diagram of V2O3.

    See the full article here.

    Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science

    The Advanced Photon Source at Argonne National Laboratory is one of five national synchrotron radiation light sources supported by the U.S. Department of Energy’s Office of Science to carry out applied and basic research to understand, predict, and ultimately control matter and energy at the electronic, atomic, and molecular levels, provide the foundations for new energy technologies, and support DOE missions in energy, environment, and national security.

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