By tweaking the formula for growing oxide thin films, researchers at the Oak Ridge National Laboratory achieved virtual perfection at the interface of two insulator materials.
This finding, published in the journal Advanced Materials, could have significant ramifications for creation of novel materials with applications in energy and information technologies, leading to more efficient solar cells, batteries, solid oxide fuel cells, faster transistors, and more powerful capacitors.
The atomic resolution Z-contrast images show individual silicon atoms bonded differently in graphene. (Photo by ORNL)
Electron microscopy at the Oak Ridge National Laboratory is providing unprecedented views of the individual atoms in graphene, offering scientists a chance to unlock the material’s full potential for uses from engine combustion to consumer electronics.
Graphene crystals were first isolated in 2004. They are two-dimensional (one-atom in thickness), harder than diamonds and far stronger than steel, providing unprecedented stiffness and electrical and thermal properties. By viewing the atomic and bonding configurations of individual graphene atoms, scientists are able to suggest ways to optimize materials so they are better suited for specific applications.
Researchers at Oak Ridge National Laboratory have reported progress in fabricating advanced materials at the nanoscale. The spontaneous self-assembly of nanostructures composed of multiple elements paves the way toward materials that could improve a range of energy-efficient technologies and data storage devices.
ORNL Materials Science and Technology Division researcher Amit Goyal led the effort, combining theoretical and experimental studies to understand and control the self-assembly of insulating barium zirconium oxide nanodots and nanorods within barium-copper-oxide superconducting films.
Not only is Oak Ridge National Laboratory’s Titan the world’s fastest supercomputer, it is also ranked third in energy efficiency. (Photo courtesy of ORNL)
Not only is Oak Ridge National Laboratory’s Titan the world’s most powerful supercomputer, it is also one of the most energy-efficient.
Titan came in at number three on the Green500 list. Organized by Virginia Tech’s Wu-chun Feng and Kirk Cameron, the list takes the world’s 500 most powerful supercomputers—as ranked by the Top500 list announced Monday—and reorders them according to how many calculations they can get per watt of electricity.
The Oak Ridge National Laboratory launched a new era of scientific supercomputing today with Titan, a system capable of churning through more than 20,000 trillion calculations each second—or 20 petaflops—by employing a family of processors called graphic processing units first created for computer gaming. Titan will be 10 times more powerful than ORNL’s last world-leading system, Jaguar, while overcoming power and space limitations inherent in the previous generation of high-performance computers.
Titan, which is supported by the U.S. Department of Energy, will provide unprecedented computing power for research in energy, climate change, efficient engines, materials, and other disciplines, and pave the way for a wide range of achievements in science and technology.
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/.
Oak Ridge National Laboratory raised more than $914,000 during its 2012 United Way campaign, chaired by Becky Verastegui, left, and Hurtis Hodges, center. Also pictured is ORNL Director Thom Mason. (ORNL photo by Jason Richards)
Oak Ridge National Laboratory raised more than $914,000 in its 2012 United Way campaign, which supports charitable agencies throughout the area.
ORNL United Way Campaign Chairman Hurtis Hodges said employees and retirees contributed more than $800,000 and UT-Battelle, the laboratory’s managing contractor, contributed a corporate gift of $100,000.
“The generosity of ORNL’s employees continues to make the laboratory one of the largest United Way contributors in East Tennessee,” ORNL Director Thom Mason said.
More than $25,000 was raised through special events that included a putting challenge, dunking booth, jewelry and book fairs, a cash mob, and a silent auction.
This year’s campaign focus shifted from concentrating on the total amount donated to increasing employee participation through payroll deduction, Hodges said. The strategy was in response to the loss of United Way givers in last year’s Voluntary Separation Program. The strategy worked, as ORNL saw a net gain of more than 300 new staff contributors and 41 new leadership givers, bringing the total number of staff signed up as United Way contributors to 2,004.
“Despite the economic challenges, ORNL still showed an increase in leadership givers and staff contributors,” Hodges said. “The increase in staff contributors emphasizes the importance laboratory employees place on the health of our community.”
Radiation Safety Information Computational Center directors at Tuesday’s celebration were Robert Roussin (1987-96), Bernadette Kirk (1996-2000 and 2004-11), and Tim Valentine (current). (Photo by Curtis Boles)
One of Oak Ridge National Laboratory’s longest-running institutions marked its golden anniversary on Tuesday with a recognition ceremony keynoted by U.S. Department of Energy Assistant Secretary for Nuclear Energy Peter Lyons, a press release said.
The Radiation Safety Information Computational Center has been a storehouse of invaluable nuclear computational tools and data for modeling and simulating the interaction of radiation with matter since 1962, the release said. The center acquires the state-of-the art codes and data, preserves them, and makes them accessible to the research community.
“Congratulations to the RSICC in its 50th year,” Lyons said. “RSICC’s innovative and adaptive culture has enabled the center to continuously provide a unique service to its nearly 20,000 customers around the world.”
The DOE center has expanded its software and data packages beyond radiation shielding to areas that include criticality safety, radiation protection, reactor physics, atmospheric dispersion and environmental dose, radiation dose in medical applications and space shielding applications, the release said.
The idea for the RSICC, like many that emanated from ORNL during the Cold War, can be traced to the late Alvin Weinberg, who as ORNL director chaired a president’s advisory council convened to deal with the expanse of new data emerging from the nuclear science community. The council recommended the establishment of information analysis centers.
An Oak Ridge engineering services firm with an international footprint has teamed with three Oak Ridge National Laboratory scientists to form a subsidiary and market an award-winning text analysis system.
The subsidiary, Global Security Information Analysts LLC, is the product of Professional Project Services (Pro2Serve) and the inventors of Piranha, which is software used by the military and U.S. Department of Homeland Security to analyze large sets of streaming data.
Knowing the position of missing oxygen atoms could be the key to cheaper solid oxide fuel cells with longer lifetimes. New microscopy research from the Oak Ridge National Laboratory is enabling scientists to map these vacancies at an atomic scale.
Although fuel cells hold promise as an efficient energy conversion technology, they have yet to reach mainstream markets because of their high price tag and limited lifespans. Overcoming these barriers requires a fundamental understanding of fuel cells, which produce electricity through a chemical reaction between oxygen and a fuel.
Fueling nuclear reactors with uranium harvested from the ocean could become more feasible because of a material developed by a team led by Oak Ridge National Laboratory.
The combination of ORNL’s high-capacity reusable adsorbents and a Florida company’s high-surface-area polyethylene fibers creates a material that can rapidly, selectively, and economically extract valuable and precious dissolved metals from water. The material, HiCap, vastly outperforms today’s best adsorbents, which perform surface retention of solid or gas molecules, atoms, or ions.
