Research Highlights

  • Precipitation in Pores: A Geochemical Frontier

    Scientific Achievement The effects of porous media on precipitation reactions are shown to be important, but poorly understood. Significance and Impact Geochemical reactions within rocks and soils occur in pores.  Yet, there is not agreement on how the pores affect the reactions, which limits the ability ro predict reactions in the subsurface. Research Details
  • ORNL's Plasma-arc lamp tests instrument for NASA solar probe

    To test a key instrument of a spacecraft that will fly closer to the sun than any before, engineers at Oak Ridge National Laboratory and the University of California–Berkeley used ORNL’s powerful plasma-arc lamp as a solar heat flux simulator. They tested the Fields instrument, which will make direct measurements of electric and magnetic fields, radio emissions and shock waves that course through the Sun’s atmospheric plasma.
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  • Patterning Semiconductor Building Blocks in 2D Crystals

    For the first time, researchers have synthesized lateral semiconductor heterojunctions in lithographically patterned arrays within a two-dimensional
  • Atomic Processes Control Ductility of Metallic Glasses

    A novel simulation of metallic glasses demonstrates that atomic relaxation modes during deformation depend on the density of local minima in the systems’ underlying potential energy landscape (PEL). The relaxation is mostly localized in a slowly cooled glass, but shows an extra delocalized feature (through a cascade process) in a rapidly quenched glass. This study suggests an avenue to improve ductility of metallic glasses—a long-standing challenge—through the control of the PEL and cooling histories.
  • Nanoscale Molecular Cartography of Materials

    A multimodal imaging platform was developed that, for the first time, provides co-registered topographic, nanomechanical, and chemical imaging information (via mass spectrometry) of a surface with submicron pixel size.
  • Functional Programming Computational Cores Embedded Into Traditional High Performance Computing Language Programs

    Functional Programming Computational Cores Embedded Into Traditional High Performance Computing Language Programs

    We demonstrated feasibility of embedding functional programming (FP) computational cores written in Scala into programs written in three traditional languages used to implement high performance computing (HPC) applications: Fortran, C, and C++. Measured the performance and overhead of pilot hybrid FP programs.
  • Strain Doping: A New Approach to Understanding and Controlling Advanced Materials

    Helium ions were used to control the length of a single axis in a crystal lattice, allowing for delicate manipulations of complex behavior. This accomplishment unlocks the door to engineering next-generation complex materials. Crystal lattice structure is of central importance to understanding and controlling complex materials that offer untapped potential functionality, such as high-temperature superconductivity, multiferroicity, and colossal magnetoresistivity. However, current methods of controlling lattice structure are limited.
  • Electron Beam Guides Engineering of Functional Defects

    The electron beam of a scanning transmission electron microscope was applied to generate Se vacancies in a semiconducting monolayer of MoSe2, provide energy to drive the formation and growth of inversion domains and metallic 60¡ grain boundaries, and track the dynamics. These results demonstrate it is possible to construct and characterize functional defects in monolayer materials via controllable electron-beam-guided vacancy engineering.
  • Oxygen Controls Surface of Epitaxial Manganite Films

    This atomically resolved study revealed a strong link between oxygen pressure and both surface-structure formation and growth dynamics in manganite thin films. The work provides key insights into controlling atomic-level behavior necessary for growing functional materials, such as manganese oxides  for electronic and solid-oxide fuel cell applications.
  • Confining Liquids in Hollow Nanospheres Can Yield Superior Quasi-Solid Electrolytes

    The growth and proliferation of lithium dendrites during cell recharge seriously hinder development and application of rechargeable Li-metal batteries. Researchers developed a promising strategy for fabrication of quasi−solid electrolytes with superior lithium ionic conductivities, by using a hollow silica (HS) nanosphere-film architecture that blocks dendrites. 
  • Materials scientists use ORNL's CADES to transform big data to 'smart data' for rapid image analysis

    The US Department of Energy’s Oak Ridge National Laboratory (ORNL) is home to state-of-the-art microscopes at ORNL’s Center for Nanophase Materials Sciences (CNMS). While the center’s microscopes are capable of imaging materials at incredibly small scales—down to individual atoms and even minute deviations in atomic positions determining physics of these materials—these microscopes are also capable of imaging structures extremely quickly.
  • Researchers use machine learning to find useful structural properties in neutron and x-ray data

    We live in an imperfect world—and that applies to the materials that make up our fuel cells, magnets, solar cells, batteries, and other energy technologies. Materials contain impurities and defects that influence strength and other properties.
  • True structure of pnictide 122 superconductors revealed

    High-resolution microscopy revealed an unexpected room-temperature crystal structure of the ‘122’ Ba(Fe1-xCox)2As2 superconductors, with domains similar to those in ferroelectrics but with nanometer size. This finding provides direct evidence that crystal structure and magnetism are coupled in these materials and that both are important for superconductivity.
  • New model predicts formation of stable high-entropy alloys

    Researchers devised a model that can predict which combinations of 5 or more elements will form new “high-entropy alloys.” This work, which utilizes values obtained from data mining of high-throughput calculations of binary compounds, requires no experimental or empirically derived input and advances capabilities for “materials by design.” 
  • Technique Recovers Atomic Resolution in Spectrum Images

    Researchers have demonstrated a technique for obtaining atomic-resolution information from spectrum images of thick specimens of MnFePSi compounds, which are promising for ecofriendly refrigeration. This technique allows the quantitative examination of specimens for which atomic-resolution spectroscopic analysis was previously impossible.
  • Atomic-Scale Observations Aid Mesoscale Catalyst Design

    Two phases of Mo-V-O–based oxides, M1 and M2, are promising catalysts for direct conversion of propane to acrylonitrile and are believed to act synergistically. Researchers engineered the mesoscale structure of M1- and M2-phase oxides to amplify these effects, greatly improving selectivity for propane ammoxidation. This work may result in developing cheaper chemical industrial processes using propane as the feedstock instead of propylene.
  • World's Thinnest Proton Channel

    Graphene is a single-atom thin 2-dimensional array of carbon atoms that represents a barrier that is impenetrable even to protons unless graphene membrane has macroscopic holes.
  • Electronic Excitations Transform Structure of Ceramics

    Ab initio molecular dynamics calculations reveal that electronic excitations induce a structural instability that transforms Y2Ti2O7, Gd2Ti2O7 and Sm2Ti2O7 with the pyrochlore crystal structure to an amorphous state.
  • Dynamic coupling drives conformational evolution of branched polymers in solutions

    The critical overlap concentration of polymer solutions, denoted c*, is one of the most important characteristic values of a polymer solution. This geometrically defined parameter is used to identify concentration regimes with different conformational characteristics. Because previous experiments showed that the average size of polymers remains constant below c*, it was generally accepted that within this dilute regime, the conformation of a single polymer remains invariant.
  • New Atomic Force Microscope Spectroscopy Probes Local Elasticity

    Contact resonance imaging and voltage spectroscopy based on photothermal excitation were developed to explore local bias-induced phenomena. These techniques can access nanoscale elastic properties in real time during polarization switching in ferroelectric nonvolatile memories, and during ion intercalation in batteries and supercapacitors.
  • Review Finds Ionization Can Heal or Harm Materials

    An invited review on latest advances in ion beam modification of materials provides conclusive evidence that energy loss by energetic ions to electrons (ionization) can lead to either self-healing of radiation damage created by atomic collisions or contribute to radiation damage. Hybrid computational methods that model the effects of energy transfer from electrons to atomic nuclei are experimentally validated.
  • Iodine-coordinated sulfide leads to an exceptionally stable ceramic electrolyte

    Coordination of iodine atoms within the Li3PS4 (LPS) electrolyte results in a new ceramic electrolyte with the formulation Li7P2S8I, a coordinated material between LPS and LiI. This new formulation takes advantage of the chemical stability of LiI to render an electrolyte with excellent compatability with Li anode. Additionally, the iodine coordination within the crystal structure aids in circumventing oxidative instabilities at higher electrochemical potentials.
  • Thin magnetic crystals are path to ferromagnetic graphene

    Chromium triiodide (CrI3) crystals were identified as a promising platform for studying how magnetism can enhance electronic behaviors in materials that are only a few atoms thick. Development of such ultra-thin magnetic materials may be crucial for continued advancement in miniaturization and  performance enhancement of electronic devices.
  • Researchers map atomic movements that trigger voltage fade in high-energy-density batteries

    ORNL researchers performed powder neutron diffraction experiments on high-voltage, high-capacity lithium- and manganese-rich nickel−manganese−cobalt layered composite oxides (LMR-NMCs) to obtain insights into the degradation mechanisms causing voltage fade in this high-potential cathode material. This material shows great promise for use in electric vehicle batteries if the problem of voltage fade can be addressed.
  • Scientists Connect Thermoelectric Materials and Topological Insulators

    Quantum mechanical calculations of electronic structure and transport for Bi2Te3 and its sister material Bi2Te2Se solved the long-standing puzzle of why many materials that are topological insulators are also excellent thermoelectrics. Topological insulators are a newly found class of materials where quantum mechanics and relativity in combination produce a unique conducting state on the surface.
  • Rig designed to study effect of vibration on spent nuclear fuel

    Researchers have developed an innovative system, called Cyclic Integrated Reversible-bending Fatigue Tester (CIRFT), to test and evaluate the mechanical behavior of spent nuclear fuel (SNF) under normal transportation conditions. The SNF fatigue data generated by CIRFT technology are essential in assisting back end fuel cycle reliability investigation.
  • Synergy of Ionization with Defects Creates Amorphous Track

    A colossal synergy, orders of magnitude larger than anything previously reported, has been discovered to occur between electronic energy loss by ions and pre-existing atomic defects created by elastic energy loss in single-crystal strontium titanate (SrTiO3). This synergy results in the formation of nanometer-sized amorphous tracks, but only in the region with pre-existing defects.
  • Neutron scattering characterizes dynamics in polymer family

    Understanding the interplay between structure and dynamics is the key to obtaining tailor-made materials. In the last few years, a large effort has been devoted to characterizing and relating the structure and dynamic properties in families of polymers with alkyl side groups. Now researchers have used quasielastic neutron scattering to investigate the hydrogen dynamics in poly(alkylene oxide)s with different side-chain lengths at temperatures below, as well as above, the glass transition.
  • Unexpected Magnetic Excitations in Doped Insulator Surprise Researchers

    When doping a disordered magnetic insulator material with atoms of a nonmagnetic material, the conventional wisdom is that the magnetic interactions between the magnetic ions in the material will be weakened. However, when the antiferromagnetic insulator barium manganate was doped—a process in which atoms of nonmagnetic vanadium were substituted for the manganese—the barium manganate’s magnetic excitations (i.e., its magnons) were surprisingly unreduced in strength and energy.
  • Neutron diffraction reveals promising new phosphor for white lighting in LEDs

    That college student working bleary eyed at her laptop at 3 am, that football fan capturing a brilliant touchdown with his cellphone—both are relying on new white lighting technology based on light emitting diodes (LEDs).
  • Aerodynamic levitator allows samples to "float on air"

    To you and to me, glass is a window pane, a mirror, something to hold the claret. To scientists, however, glass is a liquid that has lost its mobility, yet keeps its memory of being a liquid. Both liquids and glasses are disordered materials in which the atoms don’t establish long-range patterns. Using neutron scattering to probe that disordered system at the atomic level researchers can learn how to make new and potentially better glasses for applications such as lasers and fiber optics, as well as gain a better understanding of geological materials.
  • Materials Engineering Research at SNS Helps International Collaboration on Fusion Energy

    Scientists and engineers at ORNL are working with the ITER Organization and the Japanese Atomic Energy Agency to resolve issues with a critical component of ITER’s experimental fusion reactor. ITER is the international research facility in southeastern France whose mission is to demonstrate the feasibility of fusion as a practical long-term energy source.
  • Neutrons Probe Inner Workings of Batteries

    Designing long-lasting, reliable batteries is the key to wider acceptance of electric vehicles
  • Neutron Imaging Explored as Complementary Technique for Improving Cancer Detection

    ORNL and University of Tennessee collaboration now analyzing first results from neutron radiographs of cancerous tissue samples
  • Neutrons Show LiF Tunnel Barriers in Spin Valve Devices Improve Efficiency

    Researchers are working to discover new materials for spin valves, devices used in magnetic sensors, random access memories, and hard disk drives. Spin valves work by means of two or more conducting magnetic materials that alternate their electrical resistance depending on the alignment of the layers.
  • Studying how a protein's dynamics can take down a killer

    In the 1950s at Minimata, Japan, 900 people died and 2 million suffered life-long injury, in the form of birth defects to incapacitating neurological and muscular deformities, after swimming in and consuming fish from the bay nearby. The disaster was caused by the dumping into the bay of mercury compounds, including methylmercury. When ingested, this lethal toxin crosses the blood/brain barrier, with catastrophic results.
  • High-energy lithium-sulfur batteries

    Functional Materials for Energy High-energy lithium-sulfur batteries.
  • SNS, HFIR Experiments Help Refine Thin-Film Solar Cells

    Solar cells that convert sunlight into electricity have potential to be a widely used renewable energy source. Getting to that point, though, requires breakthroughs in their cost and their efficiency at turning sunbeams into electric current. Neutron scattering experiments conducted at Oak Ridge National Laboratory (ORNL) are helping solar cell makers obtain the hard data they need to refine their materials and manufacturing processes.
  • Theory meets experiment: structure-property relationships in an electrode material for solid-oxide fuel cells

    Fuel cell technology is one potentially very efficient and environmentally friendly way to convert the chemical energy of fuels into electricity. Solid-oxide fuel cells (SOFCs) can convert a wide variety of fuels with simpler, cheaper designs than those used in liquid electrolyte cells.
  • First-Ever Sub-Nanoscale Snapshots of Renegade Protein in Huntington's Disease

    The HFIR Bio-SANS instrument probes “disease-relevant” peptide at tenths of billionths of a meter An ORNL–University of Tennessee Graduate School of Medicine collaboration has for the first time successfully characterized the earliest structural formation of the disease type of the protein “huntingtin” that creates such havoc in Huntington’s Disease (HD). The incurable, hereditary neurological disorder is always fatal and affects 1 in 10,000 Americans.
  • Industry-Driven Research Benefits Plastics Manufacturing

    Research Contact: Gregory Beaucage Polyethylene, the most widely used plastic in the world, consists of long branching chains of atoms. Such branches make processing polyethylene difficult. The viscosity of the material increases 10-fold for every branch in a 10,000-atom chain.
  • Neutron Imaging Reveals Lithium Distribution in Lithium-Air Electrodes

    The next step in revolutionizing electric vehicle capacity Using neutron-computed tomography, researchers at the CG-1D neutron imaging instrument at Oak Ridge National Laboratory’s High Flux Isotope Reactor (HFIR) have successfully mapped the three-dimensional spatial distribution of lithium products in electrochemically discharged lithium-air cathodes.
  • Detecting the shape of polymer chains inside polyelectrolyte biomaterials

    Bio-SANS research for replacing cartilage in the spine and knees Researchers at the Bio-SANS instrument at the High Flux Isotope Reactor (HFIR) used small-angle neutron scattering (SANS) to get a first insight into the conformation of single polyelectrolyte chains in large pieces of the synthetic complex. The research pursues applications for replacement of intervertebral discs in the spine and of knee cartilage.