Oak Ridge Today

ORNL researchers receive professional society honors

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Carol Wood

Carol Wood

A.C. Buchanan

A.C. Buchanan III

Three researchers from Oak Ridge National Laboratory have received appointments and honors from their respective professional societies.

ORNL’s Carol Wood has been elected to a four-year term on the board of directors of the American Board of Toxicology. She is a senior research staff member in the Environmental Sciences Division at ORNL.

Wood was elected from more than 40 nominees. Ernest McConnell, president of ToxPath Inc., a former board member who served as president of the ABT board from 1987 to 1988, nominated her for the award. [Read more…]

ORNL research paves way for larger, safer lithium ion batteries

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Solid Electrolyte for Lithium Ion Batteries

Oak Ridge National Laboratory researchers developed a nanoporous solid electrolyte (bottom left and in detail on right) from a solvated precursor (top left). The material conducts ions 1,000 times faster than its natural bulk form and enables more energy-dense lithium ion batteries. (Submitted photo)

Looking toward improved batteries for charging electric cars and storing energy from renewable but intermittent solar and wind, scientists at Oak Ridge National Laboratory have developed the first high-performance, nanostructured solid electrolyte for more energy-dense lithium ion batteries.

Today’s lithium-ion batteries rely on a liquid electrolyte, the material that conducts ions between the negatively charged anode and positive cathode. But liquid electrolytes often entail safety issues because of their flammability, especially as researchers try to pack more energy in a smaller battery volume. Building batteries with a solid electrolyte, as ORNL researchers have demonstrated, could overcome these safety concerns and size constraints.

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ORNL’s Smith, Sokolov elected AAAS fellows

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Sean Campbell Smith and Alexei Sokolov

Oak Ridge National Laboratory researchers Sean Campbell Smith (left) and Alexei Sokolov, have been elected fellows of the American Association for the Advancement of Science. (Photo courtesy of ORNL)

Two researchers at Oak Ridge National Laboratory—Sean Campbell Smith and Alexei Sokolov—have been elected fellows of the American Association for the Advancement of Science.

Fellow is the highest honor bestowed by the AAAS, the world’s largest general scientific society and publisher of the journal Science.

Smith, director of the U.S. Department of Energy’s Center for Nanophase Materials Sciences at Oak Ridge National Laboratory, came to ORNL in 2011 from the University of Queensland in Australia, where he was the director of the Centre for Computational Molecular Science. He was cited by his AAAS peers for “distinguished contributions to the field of computational and theoretical chemistry, including fundamental advances in unimolecular rate theory and exploration of novel functionalities in nanomaterials.”

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ORNL develops lignin-based thermoplastic conversion process

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Turning lignin, a plant’s structural “glue” and a byproduct of the paper and pulp industry, into something considerably more valuable is driving a research effort headed by Amit Naskar of Oak Ridge National Laboratory.

In a cover article published in Green Chemistry, the research team describes a process that ultimately transforms the lignin byproduct into a thermoplastic—a polymer that becomes pliable above a specific temperature. Researchers accomplished this by reconstructing larger lignin molecules either through a chemical reaction with formaldehyde or by washing with methanol. Through these simple chemical processes, they created a crosslinked rubber-like material that can also be processed like plastics.

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ORNL study confirms magnetic properties of silicon nano-ribbons

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Nano-ribbons of silicon configured so the atoms resemble chicken wire could hold the key to ultrahigh density data storage and information processing systems of the future.

This was a key finding of a team of scientists led by Paul Snijders of the U.S. Department of Energy’s Oak Ridge National Laboratory.

The researchers used scanning tunneling microscopy and spectroscopy to validate first principle calculations—or models—that for years had predicted this outcome. The discovery, detailed in New Journal of Physics, validates this theory and could move scientists closer to their long-term goal of cost-effectively creating magnetism in non-magnetic materials.

“While scientists have spent a lot of time studying silicon because it is the workhorse for current information technologies, for the first time we were able to clearly establish that the edges of nano-ribbons feature magnetic silicon atoms,” said Snijders, a member of the Materials Science and Technology Division.

The surprise is that while bulk silicon is non-magnetic, the edges of nano-ribbons of this material are magnetic.

Snijders and colleagues at ORNL, Argonne National Laboratory, the University of Wisconsin and Naval Research Laboratory showed that the electron spins are ordered anti-ferromagnetically, which means they point up and down alternatingly. Configured this way, the up and down spin-polarized atoms serve as effective substitutes for conventional zeros and ones common to electron, or charge, current.

“By exploiting the electron spins arising from intrinsic broken bonds at gold-stabilized silicon surfaces, we were able to replace conventional electronically charged zeros and ones with spins pointing up and down,” Snijders said.

This discovery provides a new avenue to study low-dimensional magnetism, the researchers noted. Most importantly, such stepped silicon-gold surfaces provide an atomically precise template for single-spin devices at the ultimate limit of high-density data storage and processing.

“In the quest for smaller and less expensive magnets, electro-motors, electronics and storage devices, creating magnetism in otherwise non-magnetic materials could have far-reaching implications,” Snijders said.

The paper is available online at http://iopscience.iop.org/1367-2630/14/10/103004. This research was funded by DOE’s Office of Science, the National Science Foundation, and the Office of Naval Research.

This work was supported by the Center for Nanophase Materials Sciences at ORNL. CNMS is one of the five DOE Nanoscale Science Research Centers supported by the DOE Office of Science, premier national user facilities for interdisciplinary research at the nanoscale.

Together, the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative. The NSRCs are located at DOE’s Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge, and Sandia and Los Alamos national laboratories. For more information about the DOE NSRCs, visit http://science.energy.gov/bes/suf/user-facilities/nanoscale-science-research-centers/.