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Ames Lab Scientists' Surprising Discovery: Making Ferromagnets Stronger by Adding Non-Magnetic Element

Researchers at the U.S. Department of Energy's Ames Laboratory discovered that they could functionalize magnetic materials through a thoroughly unlikely method, by adding amounts of the virtually non-magnetic element scandium to a gadolinium-germanium alloy. It was so unlikely they called it a "counterintuitive experimental finding" in their published work on the research.

Cut U.S. Commercial Building Energy Use 29% with Widespread Controls

The U.S. could slash its energy use by the equivalent of what is currently used by 12 to 15 million Americans if commercial buildings fully used energy-efficiency controls nationwide.

How a Single Chemical Bond Balances Cells Between Life and Death

With SLAC's X-ray laser and synchrotron, scientists measured exactly how much energy goes into keeping a crucial chemical bond from triggering a cell's death spiral.

New Efficient, Low-Temperature Catalyst for Converting Water and CO to Hydrogen Gas and CO2

Scientists have developed a new low-temperature catalyst for producing high-purity hydrogen gas while simultaneously using up carbon monoxide (CO). The discovery could improve the performance of fuel cells that run on hydrogen fuel but can be poisoned by CO.

Study Sheds Light on How Bacterial Organelles Assemble

Scientists at Berkeley Lab and Michigan State University are providing the clearest view yet of an intact bacterial microcompartment, revealing at atomic-level resolution the structure and assembly of the organelle's protein shell. This work can help provide important information for research in bioenergy, pathogenesis, and biotechnology.

A Single Electron's Tiny Leap Sets Off 'Molecular Sunscreen' Response

In experiments at the Department of Energy's SLAC National Accelerator Laboratory, scientists were able to see the first step of a process that protects a DNA building block called thymine from sun damage: When it's hit with ultraviolet light, a single electron jumps into a slightly higher orbit around the nucleus of a single oxygen atom.

Researchers Find New Mechanism for Genome Regulation

The same mechanisms that separate mixtures of oil and water may also help the organization of an unusual part of our DNA called heterochromatin, according to a new study by Berkeley Lab researchers. They found that liquid-liquid phase separation helps heterochromatin organize large parts of the genome into specific regions of the nucleus. The work addresses a long-standing question about how DNA functions are organized in space and time, including how genes are silenced or expressed.

The Rise of Giant Viruses

Research reveals that giant viruses acquire genes piecemeal from others, with implications for bioenergy production and environmental cleanup.

Grasses: The Secrets Behind Their Success

Researchers find a grass gene affecting how plants manage water and carbon dioxide that could be useful to growing biofuel crops on marginal land.

SLAC Experiment is First to Decipher Atomic Structure of an Intact Virus with an X-ray Laser

An international team of scientists has for the first time used an X-ray free-electron laser to unravel the structure of an intact virus particle on the atomic level. The method dramatically reduces the amount of virus material required, while also allowing the investigations to be carried out several times faster than before. This opens up entirely new research opportunities.


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Chicago Quantum Exchange to Create Technologically Transformative Ecosystem

The University of Chicago is collaborating with the U.S. Department of Energy's Argonne National Laboratory and Fermi National Accelerator Laboratory to launch an intellectual hub for advancing academic, industrial and governmental efforts in the science and engineering of quantum information.

Department of Energy Awards Six Research Contracts Totaling $258 Million to Accelerate U.S. Supercomputing Technology

Today U.S. Secretary of Energy Rick Perry announced that six leading U.S. technology companies will receive funding from the Department of Energy's Exascale Computing Project (ECP) as part of its new PathForward program, accelerating the research necessary to deploy the nation's first exascale supercomputers.

Cynthia Jenks Named Director of Argonne's Chemical Sciences and Engineering Division

Argonne has named Cynthia Jenks the next director of the laboratory's Chemical Sciences and Engineering Division. Jenks currently serves as the assistant director for scientific planning and the director of the Chemical and Biological Sciences Division at Ames Laboratory.

Argonne-Developed Technology for Producing Graphene Wins TechConnect National Innovation Award

A method that significantly cuts the time and cost needed to grow graphene has won a 2017 TechConnect National Innovation Award. This is the second year in a row that a team at Argonne's Center for Nanoscale Materials has received this award.

Honeywell UOP and Argonne Seek Research Collaborations in Catalysis Under Technologist in Residence Program

Researchers at Argonne are collaborating with Honeywell UOP scientists to explore innovative energy and chemicals production.

Follow the Fantastic Voyage of the ICARUS Neutrino Detector

The ICARUS neutrino detector, born at Gran Sasso National Lab in Italy and refurbished at CERN, will make its way across the sea to Fermilab this summer. Follow along using an interactive map online.

JSA Awards Graduate Fellowships for Research at Jefferson Lab

Jefferson Sciences Associates announced today the award of eight JSA/Jefferson Lab graduate fellowships. The doctoral students will use the fellowships to support their advanced studies at their universities and conduct research at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) - a U.S. Department of Energy nuclear physics laboratory managed and operated by JSA, a joint venture between SURA and PAE Applied Technologies.

Muon Magnet's Moment Has Arrived

On May 31, the 50-foot-wide superconducting electromagnet at the center of the Muon g-2 experiment saw its first beam of muon particles from Fermilab's accelerators, kicking off a three-year effort to measure just what happens to those particles when placed in a stunningly precise magnetic field. The answer could rewrite scientists' picture of the universe and how it works.

Seven Small Businesses to Collaborate with Argonne to Solve Technical Challenges

Seven small businesses have been selected to collaborate with researchers at Argonne to address technical challenges as part of DOE's Small Business Vouchers Program.

JSA Names Charles Perdrisat and Charles Sinclair as Co-Recipients of its 2017 Outstanding Nuclear Physicist Prize

Jefferson Science Associates, LLC, announced today that Charles Perdrisat and Charles Sinclair are the recipients of the 2017 Outstanding Nuclear Physicist Prize. The 2017 JSA Outstanding Nuclear Physicist Award is jointly awarded to Charles Perdrisat for his pioneering implementation of the polarization transfer technique to determine proton elastic form factors, and to Charles Sinclair for his crucial development of polarized electron beam technology, which made such measurements, and many others, possible.


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Oxygen: The Jekyll and Hyde of Biofuels

Scientists are devising ways to protect plants, biofuels and, ultimately, the atmosphere itself from damage caused by an element that sustains life on earth.

The Rise of Giant Viruses

Research reveals that giant viruses acquire genes piecemeal from others, with implications for bioenergy production and environmental cleanup.

Grasses: The Secrets Behind Their Success

Researchers find a grass gene affecting how plants manage water and carbon dioxide that could be useful to growing biofuel crops on marginal land.

New Perspectives Into Arctic Cloud Phases

Teamwork provides insight into complicated cloud processes that are important to potential environmental changes in the Arctic.

Mountaintop Plants and Soils to Become Out of Sync

Plants and soil microbes may be altered by climate warming at different rates and in different ways, meaning vital nutrient patterns could be misaligned.

If a Tree Falls in the Amazon

For the first time, scientists pinpointed how often storms topple trees, helping to predict how changes in Amazonia affect the world.

Turning Waste into Fuels, Microbial Style

A newly discovered metabolic process linking different bacteria in a community could enhance bioenergy production.

Department of Energy Awards Six Research Contracts Totaling $258 Million to Accelerate U.S. Supercomputing Technology

Today U.S. Secretary of Energy Rick Perry announced that six leading U.S. technology companies will receive funding from the Department of Energy's Exascale Computing Project (ECP) as part of its new PathForward program, accelerating the research necessary to deploy the nation's first exascale supercomputers.

Electrifying Magnetism

Researchers create materials with controllable electrical and magnetic properties, even at room temperature.

One Step Closer to Practical Fast Charging Batteries

Novel electrode materials have designed pathways for electrons and ions during the charge/discharge cycle.


Ultrafast Imaging Reveals the Electron's New Clothes

Article ID: 673383

Released: 2017-04-21 06:10:31

Source Newsroom: Department of Energy, Office of Science

  • Credit: Image courtesy of Brookhaven National Laboratory

    Imaging atomic-scale electron-lattice interactions: A laser pulse (red beam coming from right) gives electrons in a manganese oxide a "kick" of energy while a high-energy electron beam (blue) probes the atomic structure. Circle- and rod-shaped blobs represent spherical and elongated electron clouds on the manganese atoms. The oxygen atoms (not shown) form regular and elongated octahedra around the manganese atoms. Varying the time delay between the pulse and the probe lets scientists directly measure time-resolved subtle shifts in atomic arrangements as the lattice responds to the kicked-up electrons. It reveals the motion of the electrons in the system being accompanied by the atomic lattice deformation it induces.

The Science

When a negatively charged electron zips through a lattice of atoms, the nearby positively charged atoms shift closer to the electron. Scientists demonstrated how the movement of electrons deforms the lattice and causes the electron to look as if it is being “dressed” by the deformation. These changes drastically alter the flow of electric current. This work offers strong evidence for the formation of polarons that are important for understanding energy transport in complex materials.

The Impact

The ultrafast electron diffraction technique used in this study can precisely follow changes of atomic and electron motion in materials. It can track motions that occur in less than a picosecond (a trillionth of a second). This work reveals the vital role of electron-lattice interactions in one material – manganites. This material could be used in data-storage devices with increased data density and reduced power requirements. In addition, scientists can use this method to study such interactions in a wide range of complex materials. Potentially, this method could be used to gain insight into the loss-free conduction of electricity.

Summary

When an electron, which is negatively charged, travels through the atomic lattice, just like the attraction between opposite ends of a magnet, the nearby positively charged atoms tend to move closer to the electron. As the atomic lattice is deformed by the attraction to the electron, the electron looks like it is being “dressed” by the lattice deformation. The resultant combined motion of the electron and the lattice deformation, known as a polaron, is a foundation in our understanding of various transport phenomena in solids. This includes the transformation from an insulator to a superconductor (resistance-free flow of charge, in which electrons pair by sharing lattice deformations). However, little was known experimentally about the dynamics of individual phonons (small energy packets or “quantum of energy” associated with, for example, a vibration of a crystal lattice) during polaron formation and motion. Scientists at Brookhaven National Laboratory, with colleagues at Rutgers University and Princeton University, have demonstrated direct experimental evidence of strong coupling between electron motion and deformations in atomic arrangements that affect the flow of current (i.e., the polaron formation) in manganite LaSr2Mn2O7. They achieved these results using a novel ultrafast ultrahigh-energy electron diffraction system developed by the lab to quantify the material’s electronic and atomic dynamics upon femtosecond laser illumination. They find that a specific lattice distortion dominates the lattice responses with its atomic constituents showing distinct one-step and two-step relaxation behaviors (scientifically referred to as a Jahn-Teller lattice distortion). This complex lattice relaxation manifests a strong interaction of phonons with the photoexcited electrons, proving that polaron transport is a key mechanism in the manganites’ colossal magnetoresistance properties, which could be used in data-storage devices with increased data density and reduced power requirements. The technique can be widely used to understand the dynamics of electrons and atoms to reveal the origins of properties of complex materials.

Funding

U.S. Department of Energy, Office of Science, Basic Energy Sciences

Publications

J. Li, W. Yin, L. Wu, P. Zhu, T. Konstantinova, J. Tao, J. Yang, S.W. Cheong, F. Carbone, J.A. Misewich, J.P. Hill, X. Wang, R.J. Cava, and Y. Zhu, “Dichotomy in ultrafast atomic dynamics as direct evidence of polaron formation in manganitesExternal link.” NPJ Quantum Materials 1, 16026 (2016). [DOI: 10.1038/npjquantmats.2016.26]