X
X
X

Filters:

Printed, Flexible and Rechargeable Battery Can Power Wearable Sensors

Nanoengineers at the University of California San Diego have developed the first printed battery that is flexible, stretchable and rechargeable. The zinc batteries could be used to power everything from wearable sensors to solar cells and other kinds of electronics. The work appears in the April 19, 2017 issue of Advanced Energy Materials.

Neutrons Provide the First Nanoscale Look at a Living Cell Membrane

A research team from the Department of Energy's Oak Ridge National Laboratory has performed the first-ever direct nanoscale examination of a living cell membrane. In doing so, it also resolved a long-standing debate by identifying tiny groupings of lipid molecules that are likely key to the cell's functioning.

How X-Rays Helped to Solve Mystery of Floating Rocks

Experiments at Berkeley Lab's Advanced Light Source have helped scientists to solve a mystery of why some rocks can float for years in the ocean, traveling thousands of miles before sinking.

Special X-Ray Technique Allows Scientists to See 3-D Deformations

In a new study published last Friday in Science, researchers at Argonne used an X-ray scattering technique called Bragg coherent diffraction imaging to reconstruct in 3-D the size and shape of grain defects. These defects create imperfections in the lattice of atoms inside a grain that can give rise to interesting material properties and effects.

Neptune: Neutralizer-Free Plasma Propulsion

The most established plasma propulsion concepts are gridded-ion thrusters that accelerate and emit a larger number of positively charged particles than those that are negatively charged. To enable the spacecraft to remain charge-neutral, a "neutralizer" is used to inject electrons to exactly balance the positive ion charge in the exhaust beam. However, the neutralizer requires additional power from the spacecraft and increases the size and weight of the propulsion system. Researchers are investigating how the radio-frequency self-bias effect can be used to remove the neutralizer altogether, and they report their work in this week's Physics of Plasmas.

Report Sheds New Insights on the Spin Dynamics of a Material Candidate for Low-Power Devices

In a report published in Nano LettersArgonne researchers reveal new insights into the properties of a magnetic insulator that is a candidate for low-power device applications; their insights form early stepping-stones towards developing high-speed, low-power electronics that use electron spin rather than charge to carry information.

Researchers Find Computer Code That Volkswagen Used to Cheat Emissions Tests

An international team of researchers has uncovered the mechanism that allowed Volkswagen to circumvent U.S. and European emission tests over at least six years before the Environmental Protection Agency put the company on notice in 2015 for violating the Clean Air Act. During a year-long investigation, researchers found code that allowed a car's onboard computer to determine that the vehicle was undergoing an emissions test.

Physicists Discover That Lithium Oxide on Tokamak Walls Can Improve Plasma Performance

A team of physicists has found that a coating of lithium oxide on the inside of fusion machines known as tokamaks can absorb as much deuterium as pure lithium can.

Scientists Perform First Basic Physics Simulation of Spontaneous Transition of the Edge of Fusion Plasma to Crucial High-Confinement Mode

PPPL physicists have simulated the spontaneous transition of turbulence at the edge of a fusion plasma to the high-confinement mode that sustains fusion reactions. The research was achieved with the extreme-scale plasma turbulence code XGC developed at PPPL in collaboration with a nationwide team.

Green Fleet Technology

New research at Penn State addresses the impact delivery trucks have on the environment by providing green solutions that keep costs down without sacrificing efficiency.


Filters:

Rensselaer Polytechnic Institute Graduates Urged to Embrace Change at 211th Commencement

Describing the dizzying pace of technological innovation, former United States Secretary of Energy Ernest J. Moniz urged graduates to "anticipate career change, welcome it, and manage it to your and your society's benefit" at the 211th Commencement at Rensselaer Polytechnic Institute (RPI) Saturday.

ORNL Welcomes Innovation Crossroads Entrepreneurial Research Fellows

Oak Ridge National Laboratory today welcomed the first cohort of innovators to join Innovation Crossroads, the Southeast region's first entrepreneurial research and development program based at a U.S. Department of Energy national laboratory.

Department of Energy Secretary Recognizes Argonne Scientists' Work to Fight Ebola, Cancer

Two groups of researchers at Argonne earned special awards from the office of the U.S. Secretary of Energy for addressing the global health challenges of Ebola and cancer.

Jefferson Science Associates, LLC Recognized for Leadership in Small Business Utilization

Jefferson Lab/Jefferson Science Associates has a long-standing commitment to doing business with and mentoring small businesses. That commitment and support received national recognition at the 16th Annual Dept. of Energy Small Business Forum and Expo held May 16-18, 2017 in Kansas City, Mo.

Rensselaer Polytechnic Institute President's Commencement Colloquy to Address "Criticality, Incisiveness, Creativity"

To kick off the Rensselaer Polytechnic Institute Commencement weekend, the annual President's Commencement Colloquy will take place on Friday, May 19, beginning at 3:30 p.m. The discussion, titled "Criticality, Incisiveness, Creativity," will include the Honorable Ernest J. Moniz, former Secretary of Energy, and the Honorable Roger W. Ferguson Jr., President and CEO of TIAA, and will be moderated by Rensselaer President Shirley Ann Jackson.

ORNL, University of Tennessee Launch New Doctoral Program in Data Science

The Tennessee Higher Education Commission has approved a new doctoral program in data science and engineering as part of the Bredesen Center for Interdisciplinary Research and Graduate Education.

SurfTec Receives $1.2 Million Energy Award to Develop Novel Coating

The Department of Energy has awarded $1.2 million to SurfTec LLC, a company affiliated with the U of A Technology Development Foundation, to continue developing a nanoparticle-based coating to replace lead-based journal bearings in the next generation of electric machines.

Ames Laboratory Scientist Inducted Into National Inventors Hall of Fame

Iver Anderson, senior metallurgist at Ames Laboratory, has been inducted into the National Inventors Hall of Fame.

DOE HPC4Mfg Program Funds 13 New Projects to Improve U.S. Energy Technologies Through High Performance Computing

A U.S. Department of Energy (DOE) program designed to spur the use of high performance supercomputers to advance U.S. manufacturing is funding 13 new industry projects for a total of $3.9 million.

Penn State Wind Energy Club Breezes to Victory in Collegiate Wind Competition

The Penn State Wind Energy Club breezed through the field at the U.S. Department of Energy Collegiate Wind Competition 2017 Technical Challenge, held April 20-22 at the National Wind Technology Center near Boulder, Colorado--earning its third overall victory in four years at the Collegiate Wind Competition.


Filters:

Casting a Wide Net

Designed molecules will provide positive impacts in energy production by selectively removing unwanted ions from complex solutions.

New Software Tools Streamline DNA Sequence Design-and-Build Process

Enhanced software tools will accelerate gene discovery and characterization, vital for new forms of fuel production.

The Ultrafast Interplay Between Molecules and Materials

Computer calculations by the Center for Solar Fuels, an Energy Frontier Research Center, shed light on nebulous interactions in semiconductors relevant to dye-sensitized solar cells.

Supercapacitors: WOODn't That Be Nice

Researchers at Nanostructures for Electrical Energy Storage, an Energy Frontier Research Center, take advantage of nature-made materials and structure for energy storage research.

Groundwater Flow Is Key for Modeling the Global Water Cycle

Water table depth and groundwater flow are vital to understanding the amount of water that plants transmit to the atmosphere.

Finding the Correct Path

A new computational technique greatly simplifies the complex reaction networks common to catalysis and combustion fields.

Opening Efficient Routes to Everyday Plastics

A new material from the Inorganometallic Catalyst Design Center, an Energy Frontier Research Center, facilitates the production of key industrial supplies.

Fight to the Top: Silver and Gold Compete for the Surface of a Bimetallic Solid

It's the classic plot of a buddy movie. Two struggling bodies team up to drive the plot and do good together. That same idea, when it comes to metals, could help scientists solve a big problem: the amount of energy consumed by making chemicals.

Saving Energy Through Light Control

New materials, designed by researchers at the Center for Excitonics, an Energy Frontier Research Center, can reduce energy consumption with the flip of a switch.

Teaching Perovskites to Swim

Scientists at the ANSER Energy Frontier Research Center designed a two-component layer protects a sunlight-harvesting device from water and heat.


Unexpected Damage Found Rippling Through Promising Exotic Nanomaterials

Article ID: 673787

Released: 2017-04-28 11:05:31

Source Newsroom: Brookhaven National Laboratory

  • Credit: Adrian Gozar.

    The new instrument, developed at Brookhaven and in use at Yale, combines atomic force microscopy (AFM) and scanning near-field optical microscopy to provide unprecedented insight into these complex nanomaterials.

  • The rough, bright patches reveal details of the never-before-seen damage dealt by the helium ion beam used to carve channels in an attempt to create the conditions for superconductivity.

UPTON, NY—Some of the most promising and puzzling phenomena in physics play out on the nanoscale, where a billionth-of-a-meter shift can make or break perfect electrical conductivity.

Now, scientists have developed a new method to probe three-dimensional, atomic-scale intricacies and chemical compositions with unprecedented precision. The breakthrough technique—described February 6 in the journal Nano Letters—combines atomic-force microscopy with near-field spectroscopy to expose the surprising damage wreaked by even the most subtle forces.

“This is like granting sight to the blind,” said lead author Adrian Gozar of Yale University. “We can finally see the all-important variations that dictate functionality at this scale and better explore both cutting-edge electronics and fundamental questions that have persisted for decades.”

Scientists from Yale University, Harvard University, and the U.S. Department of Energy’s Brookhaven National Laboratory developed the technique to determine why a particular device fabrication technique—helium-ion beam lithography—failed to create the scalable, high-performing superconducting nanowires predicted by both theory and simulation.

In previous work, heavy ion beams were used to carve 10-nm-wide channels—some 10,000 times thinner than a human hair—through custom-made materials. However, the new study revealed beam-induced damage rippling out over 50 times that distance. At this scale, that difference was both imperceptible and functionally catastrophic.

“This directly addresses the challenge of quantum computing, for example, where companies including IBM and Google are exploring superconducting nanowires but need reliable synthesis and characterization,” said study coauthor and Brookhaven Lab physicist Ivan Bozovic.

Writing with ions

One promising design for high-temperature superconducting devices is alternating superconductor-insulator-superconductor (SIS) interfaces—or so-called Josephson junctions. These are theoretically easy to fabricate by direct beam writing, assuming sufficient precision can be achieved.

Helium-ion beam lithography (HIB) was a perfect candidate, proven recently in similar materials and well suited for swift and scalable production of superconducting nanowires and Josephson junctions.

“HIB lets us focus the particle beam to less than a single nanometer and effectively ‘write’ patterns to create superconducting interfaces,” said Nicholas Litombe, who led the HIB work under the guidance of Professor Jenny Hoffman of Harvard, a coauthor of this study. “We set out to shift that technique to another class of materials: LSCO thin films.”

The collaboration started with the painstaking assembly of perfect LSCO thin films—so named for their use of lanthanum, strontium, copper, and oxygen. Bozovic’s group at Brookhaven used a technique called atomic layer-by-layer molecular beam epitaxy, which can create atomically perfect superconducting films and heterostructures.

“I have a long-standing interest and specialization in using interphase physics to induce and understand high-temperature superconductivity,” Bozovic said. “HIB gives us an entirely new way to explore these materials on the nanoscale.”

Litombe carved the ultra-precise interface channels in Bozovic’s thin films. But the immediate results were discouraging: the anticipated superconductivity was entirely suppressed when current ran through wires narrower than a couple hundred nanometers.

“Our computer models and experimental results all looked excellent, but we knew there were hidden forces at work,” Litombe said. “We needed deeper insight into the material structure.”

Cryogenic lightning rod

Material composition and electronic properties can be pinpointed through the way they absorb and emit light—a longstanding field called spectroscopy. In the instance of superconductivity, this can distinguish between the “shiny” surface of a conductive metal versus the dullness of a current-breaking insulator.

The scientists turned to scanning near-field optical microscopy (SNOM) to examine the spectroscopic sheen on the HIB pathways. But this technique, which funnels light through a gilded glass capillary, has a resolution limit of about 100 nanometers—much too large to examine the nanoscale superconducting interfaces.

Fortunately, Gozar built a specialized instrument to radically increase the spectroscopic resolution. The machine, built entirely at Brookhaven Lab and now housed at Yale, combines SNOM with atomic force microscopy (AFM). Like a record player’s needle extracting sound from the texture of vinyl, an AFM needle travels over a material and reads the atomic topography.

“Here, the AFM needle acts like a lightning rod, channeling the SNOM light down to just tens of nanometers,” Gozar said. “We have simultaneous AFM topography and spectroscopic data on the deep chemical structures.”

Crucially, Gozar’s AFM-SNOM system also operates at the cryogenic temperatures required to test these materials—a capability only offered at a few laboratories in the world.

Widespread ruin

The novel technique revealed the unexpected and widespread damage left in the wake of the helium ions. Despite the 0.5-nanometer focus of the beam, its effects rattled atoms across a 500-nanometer spread and altered the structure enough to prevent superconductivity. For nanomaterial construction, this so-called lateral straggle is utterly untenable.

“Even the slightest nudge at this scale shatters the powerful phenomena we mean to exploit,” Litombe said. “High-temperature superconductivity can have a coherence distance of just a few atoms, so this lateral effect is devastating. We are, of course, still thrilled to explore the never-before-seen details.”

Added Bozovic, “In one sense, the whole result was negative. Our initial goal of creating nanometer-thick superconducting wires was not fully accomplished. But figuring out why has opened some truly exciting doors.”

The SNOM-AFM technique is readily applicable to fields such as plasmonics for display technology and the study of the mechanism behind high-temperature superconductivity.

“The nanoscale resolution and the tomographic capabilities of the instrument, put us on the cusp of uncovering new truths about nanoscale phenomena and the technology it empowers,” Gozar said.

This research was supported by the U.S. Department of Energy’s Office of Science and the Gordon and Betty Moore Foundation.

Brookhaven National Laboratory is supported by the Office of Science of the U.S. Department of Energy. The 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.