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  • richardmitnick 2:36 pm on December 6, 2016 Permalink | Reply
    Tags: , , BNL CFN, , , Don DiMarzio,   

    From BNL: “Q&A with CFN User Don DiMarzio” 

    Brookhaven Lab

    December 6, 2016
    Ariana Tantillo
    atantillo@bnl.gov

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    Don DiMarzio. No image credit

    Don DiMarzio is an engineering fellow at Northrop Grumman and a senior scientist within the company’s advanced research, development, design, and demonstration group NG Next, where he studies nanomaterials and radio-frequency metamaterials. He is also an adjunct professor at Stony Brook University, where he teaches a nanotechnology class. Since March 2016, he has been using the advanced characterization labs at the Center for Functional Nanomaterials (CFN)—a U.S. Department of Energy (DOE) Office of Science User Facility at Brookhaven Lab—primarily to investigate nanostructures whose self-assembly is directed through DNA scaffolds. CFN physicist Oleg Gang has been developing this DNA-based technique for several years.

    Northrop Grumman is typically known for building aircraft, such as the U.S. Air Force’s B-2 stealth bomber, as well as unmanned autonomous aircraft and satellites. How does basic research come into play?

    About two years ago, Tom Vice, corporate vice president and president of Northrop Grumman Aerospace Systems, began discussing with his leadership team how to reconstitute the basic research activity that had existed in various forms earlier in the company’s history. NG Next, which includes basic research, applied research and technology development, advanced design, and rapid prototyping, emerged from these discussions. The goal of NG Next is to position Northrop Grumman at the cutting edge of science and technology and to attract the best and brightest young talent.

    NG Next’s basic research group is led by Tom Pieronek, vice president of basic research. The group has eight thrusts or topic areas relevant to the aerospace industry. One of these topics is nanomaterials, which is the focus of the Nanomaterials Group, led by Jesse Tice. I belong to this group. Other thrusts within the basic research group include semiconductor materials, plasmonics, and cognitive autonomy. The charter of our basic research organization is to do real science that is nonproprietary and publishable, in collaboration with the nation’s top universities and government labs. Any fundamental new discoveries that we think are promising may be transferred over to our applied research and prototyping groups within NG Next.

    The Center for Functional Nanomaterials (CFN) is one of five U.S. Department of Energy Nanoscale Science Research Centers and is among the many nanoscale facilities located at universities across the United States. What influenced your decision to submit a user proposal to CFN?

    After I got my PhD in solid-state physics, I did a postdoc at Brookhaven’s National Synchrotron Light Source (NSLS) in the late 1980s and really enjoyed working at Brookhaven.

    BNL NSLS
    BNL NSLS Interior
    BNL/NSLS

    After my postdoc, I became a scientist at the Grumman Corporate Research Center in Bethpage, NY, but continued my collaborations with Brookhaven on and off throughout the years.

    When Northrop Grumman leadership began planning for the new basic research group last year, I got involved. Part of my planning and development work for the group included helping to organize workshops—one in nanomaterials and the other in radio-frequency metamaterials—at our regional headquarters in southern California. For these invite-only workshops, the goal was to learn what was at the cutting edge in research, where we should focus our efforts, and who we could collaborate with.

    Our Nanomaterials Workshop provided a broad perspective on cutting-edge research, from nanomaterials synthesis and structures fabrication through fundamental properties and applications. One area that showed great potential was in nanoparticle self-assembly, and one of the major players in that field is the CFN. Although I had been working with various nanotechnologies before the establishment of NG Next, the CFN was either not established yet or our research was both applied and highly proprietary. But with the establishment of the basic research group within NG Next, it became clear that there was a definite opportunity for collaboration, especially considering that the way CFN is set up aligns with NG Next’s charter to publish, make presentations, and collaborate.

    When I learned about CFN physicist Oleg Gang’s work on exploiting DNA to direct the self-assembly of nanoparticles, I became very intrigued. I was particularly impressed with the strength and flexibility of this DNA origami scaffolding to fabricate a wide range of structures relevant for device and materials applications, and the ability to transition these assemblies from “soft” to “hard” while preserving key functionalities. Northrop Grumman sees this work as a potentially ground-breaking area that may lead to revolutionary new fabrication capability for everything from sensor systems to structural composites.

    While most of NG Next’s basic research group is in California, I am here on Long Island (at our Bethpage facility), so CFN is conveniently located near where I work and live. The group in California is currently building out its own labs that will be separate from our traditional applied laboratories. As an existing facility with state-of-the-art equipment and expertise in nanomaterials synthesis, device fabrication, and advanced characterization, CFN was the perfect complement to our West Coast research operations.

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    Gold nanoparticles are coordinated by DNA origami octahedron into the prescribed cluster, as obtained from the 3D transmission electron microscopy reconstruction (based on Y. Tian et al. Nature Nanotechnology 10, 637–644, 2015).

    Are you working on any other projects at CFN besides the directed self-assembly?

    In nanomaterials research, I am supporting principal investigators who are using CFN’s advanced characterization tools, particularly those in microscopy, to look at cutting-edge 2D materials like tin selenide (SnSe) and black phosphorous, in collaboration with our university partners.

    For our nanomaterials work, I am also collaborating with an NG Next group involved in plasmonics research, leveraging our DNA assembly work to fabricate new and unique optical structures.

    What are some of the characterization techniques you use at CFN?

    To probe the composition of the DNA-based nanostructures, we focus on small-angle x-ray scattering (SAXS) and transmission electron microscopy (TEM). To probe the chemical states of 2D materials and devices, we use energy-dispersive x-ray spectroscopy and electron energy-loss spectroscopy. In addition to these traditional microscopy techniques, we employ aberration-corrected low-energy electron microscopy (LEEM) and angle-resolved photoemission spectroscopy (ARPES) for some of our 2D materials. This latter technique is important because the band structure, or electronic energy levels, of 2D materials often has directional dependence.

    Your work at CFN sounds like it could also benefit from the advanced characterization methods at the National Synchrotron Light Source II (NSLS-II). Are you collaborating with NSLS-II or do you have plans to?

    BNL NSLS II
    BNL NSLS Interior
    BNL/NSLS-II

    Plans are in the works for experiments at the NSLS-II, building on our current efforts at the CFN. We will be working with CFN scientists Dario Stacchiola and Jerzy Sadowski on the new LEEM/ARPES system during its commissioning in January, and we are evaluating the use of synchrotron SAXS for large-volume data acquisition from nanomaterials for additive manufacturing.

    Our leadership is very supportive of our interactions with Brookhaven’s DOE Office of Science User Facilities and would like to solidify relationships for the long term.

    How has it been coming back to Brookhaven more than 30 years later?

    Even though I work for Northrop Grumman, I feel like I am part of the family here at CFN. I am working at CFN pretty much every day. From the start, CFN leadership has been very accommodating. They helped us get rapid access while we started negotiations on our CRADA [cooperative research and development agreement] and submitted our long-range user proposals for the directed assembly and 2D materials projects.

    Since I arrived, CFN staff scientists have been very helpful with training on laboratory equipment such as the SAXS, TEM, and scanning TEM (STEM) systems. The CFN group leads have been particularly helpful in facilitating timely sample preparation, such as that with the focused-ion beam, and with scheduling the use of characterization tools.

    You mentioned you are at CFN basically every day. What keeps you coming back?

    I feel like a kid in a candy shop here. Everyone who works here is passionate about what they do, so coming in every day is something I look forward to. I have my own spare office, close to the group leaders who I am working with. Although I primarily work with Oleg, I get to interact with many other staff scientists and postdocs, not only through my research but also through my volunteer work at CFN. I am the elected vice chair of the CFN Users’ Executive Committee and co-chair of the 2017 NSLS-II & CFN Joint Users’ Meeting.

    How did you become interested in nanomaterials?

    Years ago, I was doing applied research in photocatalysis involving the use of titanium dioxide nanoparticles to create self-decontaminating surfaces—a DARPA [Defense Advanced Research Projects Agency] project. Subsequently, I got involved in developing lightweight carbon nanotube based electrical cables for Department of Defense applications. The carbon nanotube work is ongoing at Northrop Grumman, with applications for space systems and air platforms. Although these applications are important, my turn to basic research was rooted in the NG Next vision to investigate fundamental phenomena that will enable new game-changing technologies that will have applications to both Northrop Grumman’s traditional customers and future technology marketplaces.

    See the full article here .

    Please help promote STEM in your local schools.

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    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 8:13 am on September 2, 2016 Permalink | Reply
    Tags: 2016 Microscopy Today Innovation Awards, , BNL CFN, , Nathalie Bouet, , X-ray scanning microscope   

    From Brookhaven: Women in STEM – “When Nanofabrication Leads to Nanoscience: Optics Developed at the CFN Bring NSLS-II’s Ultra-Bright x-rays into Focus for Scientific Imaging” Nathalie Bouet 

    Brookhaven Lab

    August 30, 2016
    Ariana Tantillo
    atantillo@bnl.gov

    Optics are critical components in a one-of-a-kind x-ray microscope that was recognized with a 2016 Microscopy Today Innovation Award and named a 2016 R&D 100 Award finalist.

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    Nathalie Bouet, who leads Brookhaven’s fabrication of multilayer Laue lenses, uses scanning electron microscopy at the Center for Functional Nanomaterials to image the multilayer after it has been grown. She measures the exact positioning of the layers, making sure these measurements match those expected from her team’s theoretical multilayer design. This quality check is needed before the multilayer can be transformed into usable optics for the microscope.

    At the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory, nanofabrication—making structures or devices as small as a few atoms in size—is a daily occurrence at the Center for Functional Nanomaterials, a DOE Office of Science User Facility. Scientists at the National Synchrotron Light Source II (NSLS-II), another DOE Office of Science User Facility at Brookhaven, have been using CFN facilities to develop advanced x-ray focusing optics called multilayer Laue lenses (MLL). These optics have been incorporated into an x-ray scanning microscope installed at the Hard X-ray Nanoprobe (HXN) beamline, where they focus the extremely bright beams of “hard” (high energy) x-rays produced by NSLS-II to nanometer dimensions. Recently, this MLL-based microscope—the only one of its kind—was recognized with one of ten 2016 Microscopy Today Innovation Awards and was named a 2016 finalist for the R&D 100 Awards, which annually celebrate the world’s 100 most innovative technologies.

    “These honors recognize the full extent of the development and construction of the microscope, including all of the research and development work on MLL we’ve done at the CFN,” said NSLS-II physicist Nathalie Bouet, who is leading MLL fabrication at Brookhaven.

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    Inside the transmission electron microscopy sample preparation room at the Center for Functional Nanomaterials, Juan Zhou uses a polishing system to prepare a multilayer Laue lens.

    To achieve scientific imaging with extremely high spatial resolution, the optics are integrated onto a custom-built microscope with fine motors that allow extremely accurate positioning, active feedback controls that provide vibrational stability, and components that minimize thermal drifts. With this hardware, the microscope has a resolution equivalent to 50,000 times smaller than a grain of sand. Scientists at NSLS-II use the microscope to collect elemental, structural, and chemical information on everything from soil samples to biological proteins and battery materials.

    Named after physicist Max von Laue, who won the 1914 Nobel Prize in physics for his discovery of x-ray diffraction by crystals, the lenses are made up of several thousand alternating layers of two materials: silicon and tungsten silicide. To grow MLL, the scientists use a deposition system at NSLS-II that individually deposits each layer onto a silicon substrate. Layers are deposited according to a precisely controlled thickness gradient, with the thinnest layers (a few nanometers) laid first and the thickest ones (up to 25 nanometers) last.

    Because even the slightest error in the multilayer stack can have a significant impact on the properties of the optics and thus, the focusing of the x-ray beam, the scientists need to analyze carefully the quality of the stack after it has been grown. Using high-resolution scanning electron microscopy at the CFN, they image the multilayer to measure the exact positioning of the layers. They compare their measurements to those expected from the theoretical multilayer design, applying this information to correct any deviations.

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    The multilayer Laue lens module is part of the x-ray microscope (seen above in a vacuum chamber) installed at the National Synchrotron Light Source II’s Hard X-ray Nanoprobe beamline.

    Once the multilayer stack passes the quality test, the next step is to transform it into usable optics for the microscope. To convert the multilayer stack into optics that can be illuminated in transmission, scientists precisely extract very thin sections of the stack—a very challenging endeavor.

    “Sectioning is difficult because the width of the slices is significantly smaller than the thickness of the stacked layers sitting on top of the substrate,” said Brookhaven scientist Juan Zhou, a member of Bouet’s team. As a result, the multilayer sections are very susceptible to bending. If the sections contain any deformations, the lenses cannot effectively focus the x-ray beam. Therefore, very precise sectioning is crucial to ensuring that the lenses can bring x-rays into optimal focus.

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    Scientists used mechanical polishing and focused-ion beam milling to fabricate the multilayer Laue lens (MLL) seen in the above scanning electron microscope image. They glued a piece of silicon (Si) on top of the multilayer film to protect it from being damaged during the lens fabrication process.

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    This scanning electron microscope image shows the cross-section of a multilayer Laue lens (MLL) with a thickness of 43 micrometers. The cap layer (2 micrometers thick) gives the multilayer additional protection—beyond the protection offered by the glued silicon (Si) layer—against fabrication damages.

    At the CFN, scientists use one of two sectioning techniques, depending on the intrinsic characteristics of the multilayer, the energy of the x-rays that will be used, and the focal length of the lens (the distance between the lens and its focal point, where the x-rays converge). The first technique is based on mechanical polishing, in which both sides of the multilayer are “gritted” down with progressively finer abrasives until the desired thickness and smoothness of the sections are achieved. The second, developed at Brookhaven, is a patented technique based on reactive-ion etching—the removal or “etching” away of a material from its surface through bombardment with a plasma of chemically reactive ions. With both techniques, the scientists often use a focused-ion beam as a final polishing tool.

    Because the lenses are one-dimensional focusing optics, a pair of them is needed to make a focused beam in both directions. As a result, the spacing between the two lenses and the quality of their alignment impact the size of the x-ray beam.

    So far, Bouet’s team has succeeded in focusing x-rays down to 11 nanometers with MLL. But efforts are underway to push the focusing even further and to maximize the number of photons in the focused beam so that HXN users can take full advantage of NSLS-II’s brightness. The team is developing MLL with a “wedged” shape, in which the layers are tilted so that their thickness differs at both ends of the substrate. (The “flat” lenses of the microscope currently in use at the HXN beamline are of equal thickness on both sides of the substrate.) Introducing a gradient inside the multilayer means each layer forms a slightly different angle than the one before it. This geometry allows MLL to diffract x-rays more efficiently; early tests have demonstrated that the wedged lenses make use of 27 percent of the x-ray beam, twice the amount used by a flat MLL.

    The other members of the microscope development team are Brookhaven physicists Yong Chu (HXN beamline group leader), Xiaojing Huang, Evgeny Nazaretski, and Hanfei Yan, design engineer Brian Mullany, technical specialist Dennis Kuhne, software analyst Kenneth Lauer, as well as DOE Argonne National Lab engineer Deming Shu.

    See the full article here .

    Please help promote STEM in your local schools.

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    BNL Campus

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 4:05 pm on March 15, 2016 Permalink | Reply
    Tags: , , BNL CFN,   

    From BNL: “Brookhaven Lab Facilities Team Up to Offer Beamline for Cutting-Edge Science” 

    Brookhaven Lab

    March 15, 2016
    Chelsea Whyte

    The Coherent Soft X-ray Scattering and Spectroscopy (CSX-2) beamline at the National Synchrotron Light Source II, which hosted its first users in February, was built in partnership with the Center for Functional Nanomaterials

    One of the most recent capabilities to begin hosting scientific users at the National Synchrotron Light Source II (NSLS-II) was built in partnership with the Center for Functional Nanomaterials (CFN), both of which are U.S. Department of Energy (DOE) Office of Science User Facilities located at Brookhaven National Laboratory.

    BNL NSLS II
    BNL NSLS-II Interior
    NSLS II

    BNL Center for Functional Nanomaterials interior
    CFN

    The Coherent Soft X-ray Scattering and Spectroscopy (CSX-2) beamline provides soft x-rays that are perfectly suited to the research needs of catalysis scientists visiting Brookhaven’s nanocenter.

    BNL NSLS II Coherent Soft X-ray Scattering and Spectroscopy (CSX-2) beamline
    Coherent Soft X-ray Scattering and Spectroscopy (CSX-2) beamline

    Combining these x-rays with a CFN endstation is a perfect marriage then.

    “The Center for Functional Nanomaterials is a cutting-edge facility in its own right, but now it’s also a path to bring users to NSLS-II,” said CFN Director Emilio Mendez. “I look forward to the innovative science made possible at the intersection of the capabilities at CFN and NSLS-II.”

    “The synergy between our two institutions strengthens us both,” said John Hill, Director of NSLS-II. “Partnerships like the one with CFN allow us to make the most of the expertise and facilities that make Brookhaven unique.”

    The CSX-2 beamline is well-suited to research in energy production and storage, with an emphasis on studying surface chemical processes relevant in heterogeneous catalysis in situ and in operando – as they would work in real time close to real world conditions. The beamline is also suited for studying processes in environmental and atmospheric chemistry.

    “Most of our users study model systems for catalysis,” said Ira Waluyo, a beamline scientist at CSX-2 “They can bring samples ranging from single crystals to nanoparticles to the beamline, and when they expose the samples to the reactant gases, they study how the catalyst and reactants evolve during a reaction. When they increase the temperature of the sample or change the composition or pressure of the gases, they can study how the catalyst is transformed and what new chemical species are formed on the surface. Our users can then pinpoint what exactly makes a catalyst active in a particular reaction.”

    The study of catalysts is an exploration of nanoscale interface science – research into the phenomena occurring as chemical reactions take place on the scale of a billionth of a meter. The ambient pressure photoelectron spectroscopy (APPES) endstation at CSX-2 allows scientists to do experiments that would normally require ultra-high vacuum conditions to be performed at pressures closer to realistic conditions.

    “Allowing scientists to study materials for energy solutions in operando is one of the benefits here. The understanding of these interactions will help us to engineer catalysts that work better and cost less,” said Anibal Boscoboinik, a CFN staff scientist and partner at CSX-2. “Industrial researchers can use the gained knowledge to engineer catalysts for energy transformations at lower cost and with fewer environmental impacts.”

    The APPES endstation was provided by CFN, while the infrastructure of the beamline was part of the NSLS-II Project. CSX-2 will dedicate about a quarter of its available research hours to scientific users from the nanocenter, while the rest of the time will be available for users from the light source.

    “With the capabilities already available at the CFN and this new beamline, we have complementary techniques available to scientists,” Boscoboinik said. Compared to the X1A1 beamline at NSLS, where the APPES endstation was previously located, CSX-2 has a larger energy range, much higher resolution, and at least 100 times more flux “This means we can now look at core levels we could not look at before and we get better quality data with better resolved features and less noise over a shorter period of time,” Waluyo said.

    “This is an exciting time and we are thrilled to be part of it,” Boscoboinik said.

    See the full article here .

    Please help promote STEM in your local schools.

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    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 5:59 pm on February 5, 2016 Permalink | Reply
    Tags: , BNL CFN, ,   

    From BNL: “Scientists Guide Gold Nanoparticles to Form “Diamond” Superlattices” 

    Brookhaven Lab

    February 4, 2016
    Karen McNulty Walsh, (631) 344-8350
    Peter Genzer, (631) 344-3174

    DNA scaffolds cage and coax nanoparticles into position to form crystalline arrangements that mimic the atomic structure of diamond.

    Using bundled strands of DNA to build Tinkertoy-like tetrahedral cages, scientists at the U.S. Department of Energy’s Brookhaven National Laboratory have devised a way to trap and arrange nanoparticles in a way that mimics the crystalline structure of diamond. The achievement of this complex yet elegant arrangement, as described in a paper published February 5, 2016, in Science, may open a path to new materials that take advantage of the optical and mechanical properties of this crystalline structure for applications such as optical transistors, color-changing materials, and lightweight yet tough materials.

    “We solved a 25-year challenge in building diamond lattices in a rational way via self-assembly,” said Oleg Gang, a physicist who led this research at the Center for Functional Nanomaterials (CFN) at Brookhaven Lab in collaboration with scientists from Stony Brook University, Wesleyan University, and Nagoya University in Japan.

    The scientists employed a technique developed by Gang that uses fabricated DNA as a building material to organize nanoparticles into 3D spatial arrangements. They used ropelike bundles of double-helix DNA to create rigid, three-dimensional frames, and added dangling bits of single-stranded DNA to bind particles coated with complementary DNA strands.

    “We’re using precisely shaped DNA constructs made as a scaffold and single-stranded DNA tethers as a programmable glue that matches up particles according to the pairing mechanism of the genetic code—A binds with T, G binds with C,” said Wenyan Liu of the CFN, the lead author on the paper. “These molecular constructs are building blocks for creating crystalline lattices made of nanoparticles.”
    The difficulty of diamond

    As Liu explained, “Building diamond superlattices from nano- and micro-scale particles by means of self-assembly has proven remarkably difficult. It challenges our ability to manipulate matter on small scales.”

    The reasons for this difficulty include structural features such as a low packing fraction—meaning that in a diamond lattice, in contrast to many other crystalline structures, particles occupy only a small part of the lattice volume—and strong sensitivity to the way bonds between particles are oriented. “Everything must fit together in just such a way without any shift or rotation of the particles’ positions,” Gang said. “Since the diamond structure is very open, many things can go wrong, leading to disorder.”

    “Even to build such structures one-by-one would be challenging,” Liu added, “and we needed to do so by self-assembly because there is no way to manipulate billions of nanoparticles one–by–one.”

    Gang’s previous success using DNA to construct a wide range of nanoparticle arrays suggested that a DNA-based approach might work in this instance.

    DNA guides assembly

    The team first used the ropelike DNA bundles to build tetrahedral “cages”—a 3D object with four triangular faces. They added single-stranded DNA tethers pointing toward the interior of the cages using T,G,C,A sequences that matched up with complementary tethers attached to gold nanoparticles. When mixed in solution, the complementary tethers paired up to “trap” one gold nanoparticle inside each tetrahedron cage.

    Double stranded DNA bundles (gray) form tetrahedral cages
    Schematic illustration of the experimental strategy: Double stranded DNA bundles (gray) form tetrahedral cages. Single stranded DNA strands on the edges (green) and vertices (red) match up with complementary strands on gold nanoparticles. This results in a single gold particle being trapped inside each tetrahedral cage, and the cages binding together by tethered gold nanoparticles at each vertex. The result is a crystalline nanoparticle lattice that mimics the long-range order of crystalline diamond. The images below the schematic are (left to right): a reconstructed cryo-EM density map of the tetrahedron, a caged particle shown in a negative-staining TEM image, and a diamond superlattice shown at high magnification with cryo-STEM.

    The arrangement of gold nanoparticles outside the cages was guided by a different set of DNA tethers attached at the vertices of the tetrahedrons. Each set of vertices bound with complementary DNA tethers attached to a second set of gold nanoparticles.

    When mixed and annealed, the tetrahedral arrays formed superlattices with long-range order where the positions of the gold nanoparticles mimics the arrangement of carbon atoms in a lattice of diamond, but at a scale about 100 times larger.

    “Although this assembly scenario might seem hopelessly unconstrained, we demonstrate experimentally that our approach leads to the desired diamond lattice, drastically streamlining the assembly of such a complex structure,” Gang said.

    The proof is in the images. The scientists used cryogenic transmission electron microscopy (cryo-TEM) to verify the formation of tetrahedral frames by reconstructing their 3D shape from multiple images. Then they used in-situ small-angle x-ray scattering (SAXS) at the National Synchrotron Light Source (NSLS), and cryo scanning transmission electron microscopy (cryo-STEM) at the CFN, to image the arrays of nanoparticles in the fully constructed lattice.

    “Our approach relies on the self-organization of the triangularly shaped blunt vertices of the tetrahedra (so called ‘footprints’) on isotropic spherical particles. Those triangular footprints bind to spherical particles coated with complementary DNA, which allows the particles to coordinate their arrangement in space relative to one another. However, the footprints can arrange themselves in a variety of patterns on a sphere. It turns that one particular placement is more favorable, and it corresponds to the unique 3D placement of particles that locks the diamond lattice,” Gang said.

    The team supported their interpretation of the experimental results using theoretical modeling that provided insight about the main factors driving the successful formation of diamond lattices.

    Sparkling implications

    “This work brings to the nanoscale the crystallographic complexity seen in atomic systems,” said Gang, who noted that the method can readily be expanded to organize particles of different material compositions. The group has demonstrated previously that DNA-assembly methods can be applied to optical, magnetic, and catalytic nanoparticles as well, and will likely yield the long-sought novel optical and mechanical materials scientists have envisioned.

    “We’ve demonstrated a new paradigm for creating complex 3D-ordered structures via self-assembly. If you can build this challenging lattice, the thinking is you can build potentially a variety of desired lattices,” he said.

    This work was funded by the DOE Office of Science (BES). CFN and NSLS are DOE Office of Science User Facilities.

    See the full article here .

    Please help promote STEM in your local schools.

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    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 4:04 pm on July 28, 2015 Permalink | Reply
    Tags: , , , BNL CFN, ,   

    From BNL: “New Computer Model Could Explain how Simple Molecules Took First Step Toward Life” 

    Brookhaven Lab

    July 28, 2015
    Alasdair Wilkins

    Two Brookhaven researchers developed theoretical model to explain the origins of self-replicating molecules

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    Brookhaven researchers Sergei Maslov (left) and Alexi Tkachenko developed a theoretical model to explain molecular self-replication.

    Nearly four billion years ago, the earliest precursors of life on Earth emerged. First small, simple molecules, or monomers, banded together to form larger, more complex molecules, or polymers. Then those polymers developed a mechanism that allowed them to self-replicate and pass their structure on to future generations.

    We wouldn’t be here today if molecules had not made that fateful transition to self-replication. Yet despite the fact that biochemists have spent decades searching for the specific chemical process that can explain how simple molecules could make this leap, we still don’t really understand how it happened.

    Now Sergei Maslov, a computational biologist at the U.S. Department of Energy’s Brookhaven National Laboratory and adjunct professor at Stony Brook University, and Alexei Tkachenko, a scientist at Brookhaven’s Center for Functional Nanomaterials (CFN), have taken a different, more conceptual approach. They’ve developed a model that explains how monomers could very rapidly make the jump to more complex polymers. And what their model points to could have intriguing implications for CFN’s work in engineering artificial self-assembly at the nanoscale. Their work is published in the July 28, 2015 issue of The Journal of Chemical Physics.

    To understand their work, let’s consider the most famous organic polymer, and the carrier of life’s genetic code: DNA. This polymer is composed of long chains of specific monomers called nucleotides, of which the four kinds are adenine, thymine, guanine, and cytosine (A, T, G, C). In a DNA double helix, each specific nucleotide pairs with another: A with T, and G with C. Because of this complementary pairing, it would be possible to put a complete piece of DNA back together even if just one of the two strands was intact.

    While DNA has become the molecule of choice for encoding biological information, its close cousin RNA likely played this role at the dawn of life. This is known as the RNA world hypothesis, and it’s the scenario that Maslov and Tkachenko considered in their work.

    The single complete RNA strand is called a template strand, and the use of a template to piece together monomer fragments is what is known as template-assisted ligation. This concept is at the crux of their work. They asked whether that piecing together of complementary monomer chains into more complex polymers could occur not as the healing of a broken polymer, but rather as the formation of something new.

    “Suppose we don’t have any polymers at all, and we start with just monomers in a test tube,” explained Tkachenko. “Will that mixture ever find its way to make those polymers? The answer is rather remarkable: Yes, it will! You would think there is some chicken-and-egg problem—that, in order to make polymers, you already need polymers there to provide the template for their formation. Turns out that you don’t really.”

    Instilling memory

    2
    A schematic drawing of template-assisted ligation, shown in this model to give rise to autocatalytic systems. No image credit.

    Maslov and Tkachenko’s model imagines some kind of regular cycle in which conditions change in a predictable fashion—say, the transition between night and day. Imagine a world in which complex polymers break apart during the day, then repair themselves at night. The presence of a template strand means that the polymer reassembles itself precisely as it was the night before. That self-replication process means the polymer can transmit information about itself from one generation to the next. That ability to pass information along is a fundamental property of life.

    “The way our system replicates from one day cycle to the next is that it preserves a memory of what was there,” said Maslov. “It’s relatively easy to make lots of long polymers, but they will have no memory. The template provides the memory. Right now, we are solving the problem of how to get long polymer chains capable of memory transmission from one unit to another to select a small subset of polymers out of an astronomically large number of solutions.”

    According to Maslov and Tkachenko’s model, a molecular system only needs a very tiny percentage of more complex molecules—even just dimers, or pairs of identical molecules joined together—to start merging into the longer chains that will eventually become self-replicating polymers. This neatly sidesteps one of the most vexing puzzles of the origins of life: Self-replicating chains likely need to be very specific sequences of at least 100 paired monomers, yet the odds of 100 such pairs randomly assembling themselves in just the right order is practically zero.

    “If conditions are right, there is what we call a first-order transition, where you go from this soup of completely dispersed monomers to this new solution where you have these long chains appearing,” said Tkachenko. “And we now have this mechanism for the emergence of these polymers that can potentially carry information and transmit it downstream. Once this threshold is passed, we expect monomers to be able to form polymers, taking us from the primordial soup to a primordial soufflé.”

    While the model’s concept of template-assisted ligation does describe how DNA—as well as RNA—repairs itself, Maslov and Tkachenko’s work doesn’t require that either of those was the specific polymer for the origin of life.

    “Our model could also describe a proto-RNA molecule. It could be something completely different,” Maslov said.

    Order from disorder

    The fact that Maslov and Tkachenko’s model doesn’t require the presence of a specific molecule speaks to their more theoretical approach.

    “It’s a different mentality from what a biochemist would do,” said Tkachenko. “A biochemist would be fixated on specific molecules. We, being ignorant physicists, tried to work our way from a general conceptual point of view, as there’s a fundamental problem.”

    That fundamental problem is the second law of thermodynamics, which states that systems tend toward increasing disorder and lack of organization. The formation of long polymer chains from monomers is the precise opposite of that.

    “How do you start with the regular laws of physics and get to these laws of biology which makes things run backward, which make things more complex, rather than less complex?” Tkachenko queried. “That’s exactly the jump that we want to understand.”

    Applications in nanoscience

    The work is an outgrowth of efforts at the Center for Functional Nanomaterials, a DOE Office of Science User Facility, to use DNA and other biomolecules to direct the self-assembly of nanoparticles into large, ordered arrays. While CFN doesn’t typically focus on these kinds of primordial biological questions, Maslov and Tkachenko’s modeling work could help CFN scientists engaged in cutting-edge nanoscience research to engineer even larger and more complex assemblies using nanostructured building blocks.

    “There is a huge interest in making engineered self-assembled structures, so we were essentially thinking about two problems at once,” said Tkachenko. “One is relevant to biologists, and second asks whether we can engineer a nanosystem that will do what our model does.”

    The next step will be to determine whether template-aided ligation can allow polymers to begin undergoing the evolutionary changes that characterize life as we know it. While this first round of research involved relatively modest computational resources, that next phase will require far more involved models and simulations.

    Maslov and Tkachenko’s work has solved the problem of how long polymer chains capable of information transmission from one generation to the next could emerge from the world of simple monomers. Now they are turning their attention to how such a system could naturally narrow itself down from exponentially many polymers to only a select few with desirable sequences.

    “What we needed to show here was that this template-based ligation does result in a set of polymer chains, starting just from monomers,” said Tkachenko. “So the next question we will be asking is whether, because of this template-based merger, we will be able to see specific sequences that will be more ‘fit’ than others. So this work sets the stage for the shift to the Darwinian phase.”

    This work was supported by the DOE Office of Science.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    BNL Campus

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 8:51 am on June 5, 2015 Permalink | Reply
    Tags: , , BNL CFN,   

    From BNL: “National Synchrotron Light Source II and Center for Functional Nanomaterials Users’ Meeting Recap” 

    Brookhaven Lab

    June 2, 2015
    Chelsea Whyte

    In the middle of May, the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory hosted hundreds of scientists for the annual NSLS-II & CFN Users’ Meeting. The long-awaited opening of NSLS-II was reflected in the theme: “It’s Showtime!”

    They joined Brookhaven Lab Director Doon Gibbs for an update on Brookhaven’s scientific program, as well as Tanja Pietrass, the Director of the Chemical Sciences, Geosciences, and Biosciences Division at the Department of Energy’s Office of Basic Energy Sciences, who spoke about the direction of research across the division.

    “Our vision is to be the leading Department of Energy multiprogram laboratory with recognized impact on national science needs,” Gibbs said. He spoke of the Lab’s focus on its world-class programs, including leadership in photon sciences – which encompasses NSLS-II – and energy sciences, along with an increased focus on data-driven computational science and on applied science. Serving scientists at NSLS-II and CFN, which are both DOE Office of Science User Facilities, is an essential component of Brookhaven’s recipe for success in these endeavors.

    In her update on programs in DOE’s Office of Basic Energy Sciences, Pietrass emphasized the new Office of Technology Transitions, which was formed to coordinate and streamline all activities that go into taking research results directly to the marketplace. She highlighted exciting innovations and discoveries at the 32 Energy Frontier Research Centers – which she called a “priority for the Secretary of Energy” – all but one of which have direct involvement with the National Laboratories.

    “The user facilities are really a tremendous resource and the fact that they are available to all researchers in the community is a tremendous opportunity,” Pietrass said. “The fact that we have facilities like [NSLS-II and CFN] really gives us an advantage over other nations in terms of being able to produce great research.”

    Following on, Emilio Mendez, Director of the Center for Functional Nanomaterials, and John Hill, Director of NSLS-II, gave updates on the status of these facilities.

    Center for Functional Nanomaterials

    BNL Center for Functional Nanomaterials
    BNL Center for Functional Nanomaterials interior
    CFN

    Mendez reviewed the growth of the CFN user base, which has increased from 100 scientists in 2008 to the current 473 users per year.

    “Not only do we have a large number of users, but they are productive and impactful,” he said. Publications based on work at CFN have increased substantially, with a significant number based on collaborative work between visiting scientists and staff at CFN. “This intellectual collaboration distinguishes CFN.”

    The facility is also changing. Two major additions of equipment were installed and started operations in the last year: A pulsed laser deposition system, which uses a high-powered laser to vaporize materials and deposit them in layers on a substrate, and a new low-energy electron microscope.

    The former can perform experiments up to 950 degrees and will be a “very useful, powerful and versatile tool,” Mendez said. The latter enables real-time imaging of materials in situ, with spatial resolution down to two nanometers. This microscope will eventually be installed at one of the beamlines funded by the NEXT project at NSLS-II. In the meantime, CFN is operating the microscope with a UV lamp to do some limited photoemission spectroscopy.

    Coming soon at CFN will be a dedicated transmission electron microscope, which will operate under high temperatures and high pressures—capabilities well-suited for studying crystal growth and catalysts as they operate. It will be available for users within the next year, Mendez said.

    In the next few years, CFN will partner with photon sciences to complete four end-stations of beamlines at NSLS-II. These will be commissioned and operational by 2017 and will have three fully dedicated staff members.

    “A key element of our strategy has been the interaction and the synergy that we have with NSLS-II,” he said.

    National Synchrotron Light Source II

    BNL NSLS II Photo
    BNL NSLS-II Interior
    NSLS-II

    Hill began with an acknowledgement of the decades of discovery at the predecessor to NSLS-II, the National Synchrotron Light Source.

    “I have very fond memories of not just the experiments but also the people at NSLS. That facility really distinguished itself by its great community. We all take a lot of pride in what NSLS accomplished,” he said. Those accomplishments include innovations that drove synchrotron science around the globe, including the Chasman-Green lattice, monochrometer development, detector technology, infrared research, and innovations in techniques across many energy ranges that have spawned fields of study around the world.

    First light occurred at NSLS-II just three weeks after NSLS closed its doors. “Construction is over,” Hill said. “Now we are into commissioning and operations.

    The accelerator has been coming up beautifully,” he noted, having already produced more than 1600 hours of operations with commissioning ahead of schedule. “It’s performing very well, indeed.”

    All insertion devices and beamlines funded under the NSLS-II project have been commissioned, and storage of 200 milliamps has been achieved in the ring. Stability and emittance have been measured as meeting or exceeding goals.

    “That’s a really promising sign for the potential of this machine,” said Hill. “What we’re going to be famous for is the brightness of the source.”

    The goal for next year is to store a beam at 400 milliamps, and 500 milliamps the year after that. By 2017, installation activity in ring will go down, so available hours for users will go up to about 3000 hours per year. Hill estimated that the facility will host 3,000 users a year by 2019.

    “We have concrete plans to fill out about half of the experimental floor with beamlines. To fill out the rest, we are going to hold the next Strategic Planning Workshop on September 24-25 to help inform the decision-making process. I encourage you all to attend that meeting,” Hill said. That workshop will review capability gaps in the current beamline portfolio, take a look at how NSLS-II fits into the international landscape, and determine what capabilities should be pursued when selecting the final 30 beamlines for NSLS-II.

    The rest of the plenary program included a talk by Theodore Moustakas, Professor of Electrical & Computer Engineering and Materials Science at Boston University entitled, Fundamental Differences between Traditional III-V Compounds and Nitride Semiconductors. There were also updates from the Lead Scientists at the currently operating NSLS-II beamlines, including: Yong Cai, IXS; Yong Chu, HXN; Eric Dooryhee, XPD; Andrei Fluerasu, CHX; Stuart Wilkins, CSX-1 and CSX-2; and Juergen Thieme, SRX.

    Keynote: Story Collider and Crafting Stories About Science

    Ben Lillie, co-founder and director of The Story Collider, a science storytelling event and podcast held in locations all over the world, gave the keynote address, titled “Crafting stories about science.” He shared his experiences with and suggestions for communicating science in an accessible manner.

    “My first job was to design trigger systems that filter out data at RHIC,” he said, referring to the time he spent at Brookhaven’s own Relativistic Heavy Ion Collider in the year 2000. “But I decided to do something else with my life. Though, it’s not all that different. That’s the same thing you do with stories. You have to decide exactly what to keep in without distorting the science.”

    Lillie’s talk emphasized the nature of good storytelling, which was later showcased in a Story Collider event held at the Users’ Meeting banquet in the Suffolk Theater. There, five scientists from NSLS-II and CFN stood on stage to tell their own stories, small and large, about a moment of illumination during their careers.

    One of the storytellers was Sean McSweeney, a structural biologist at NSLS-II. He spoke about a time when he was using a synchrotron to solve the structure of a protein when he fully appreciated biology for the first time.

    “A moment of Damascan wonder came over me. I could see the complexity of the enzyme itself. I could trace how this thing was built. What was revealed was something no one else has seen, with exquisite detail. And this sense of wonder of seeing new structures of seeing biology in action, has stayed with me since. It’s such a useful use of light.”

    Those useful uses of light, as McSweeney put it, will expand in the coming years at NSLS-II and CFN, and the scientists who attended the meeting left informed and inspired about the future possibilities for research with synchrotron light and nano-tools at Brookhaven National Lab.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    BNL Campus

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 4:17 pm on January 28, 2015 Permalink | Reply
    Tags: , BNL CFN, Quantum Memory   

    From BNL: “Nanoscale Mirrored Cavities Amplify, Connect Quantum Memories” 

    Brookhaven Lab

    January 28, 2015
    Karen McNulty Walsh, (631) 344-8350 or Peter Genzer, (631) 344-3174

    Advance could lead to quantum computing and the secure transfer of information over long-distance fiber optic networks

    1
    Members of the MIT team (l to r): Luozhou Li, Dirk Englund, Michael Walsh, Edward Chen, and Tim Schroder. Photo credit: MIT

    The idea of computing systems based on controlling atomic spins just got a boost from new research performed at the Massachusetts Institute of Technology (MIT) and the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory. By constructing tiny “mirrors” to trap light around impurity atoms in diamond crystals, the team dramatically increased the efficiency with which photons transmit information about those atoms’ electronic spin states, which can be used to store quantum information. Such spin-photon interfaces are thought to be essential for connecting distant quantum memories, which could open the door to quantum computers and long-distance cryptographic systems.

    Crucially, the team demonstrated a spin-coherence time (how long the memory encoded in the electron spin state lasts) of more than 200 microseconds—a long time in the context of the rate at which computational operations take place. A long coherence time is essential for quantum computing systems and long-range cryptographic networks.

    “Our research demonstrates a technique to extend the storage time of quantum memories in solids that are efficiently coupled to photons, which is essential to scaling up such quantum memories for functional quantum computing systems and networks,” said MIT’s Dirk Englund, who led the research, now published in Nature Communications. Scientists at the Center for Functional Nanomaterials (CFN), a DOE Office of Science User Facility at Brookhaven Lab, helped to fabricate and characterize the materials.

    2
    A scanning electron micrograph of one of the one-dimensional diamond crystal cavities. Photo credit: MIT

    The memory elements described in this research are the spin states of electrons in nitrogen-vacancy (NV) centers in diamond. The NV consists of a nitrogen atom in the place of a carbon atom, adjacent to a crystal vacancy inside the carbon lattice of diamond. The up or down orientation of the electron spins on these NV centers can be used to encode information in a way that is somewhat analogous to how the charge of many electrons is used to encode the “0”s and “1”s in a classical computer.

    The scientists preferentially orient the NV’s spin, whose direction is naturally randomly oriented, along a particular direction. This step prepares a quantum state of “0”. From there, scientists can manipulate the electron spins into “1” or back into “0” using microwaves. The “0” state has brighter fluorescence than the “1” state, allowing scientists to measure the state in an optical microscope.

    The trick is getting the electron spins in the NV centers to hold onto the stable spin states long enough to perform these logic-gate operations—and being able to transfer information among the individual memory elements to create actual computing networks.

    “It is already possible to transfer information about the electron spin state via photons, but we have to make the interface between the photons and electrons more efficient. The trouble is that photons and electrons normally interact only very weakly. To increase the interaction between photons and the NV, we build an optical cavity—a trap for photons—around the NV,” Englund said.
    Light and mirrors

    3
    Building quantum memories on a chip: Diamond photonic crystal cavities (ladder-like structures) are integrated on a silicon substrate. Green laser light (green arrow) excites electrons on impurity atoms trapped within the cavities, picking up information about their spin states, which can then be read out as red light (red arrow) emitted by photoluminescence from the cavity. The inset shows the nitrogen-vacancy (NV)-nanocavity system, where a nitrogen atom (N) is substituted into the diamond crystal lattice in place of a carbon atom (gray balls) adjacent to a vacancy (V). Layers of diamond and air keep light trapped within these cavities long enough to interact with the nitrogen atom’s spin state and transfer that information via the emitted light. Photo credit: MIT

    These cavities, nanofabricated at Brookhaven by MIT graduate student Luozhou Li with the help of staff scientist Ming Lu of the CFN, consist of layers of diamond and air tightly spaced around the impurity atom of an NV center. At each interface between the layers there’s a little bit of reflection—like the reflections from a glass surface. With each layer, the reflections add up—like the reflections in a funhouse filled with mirrors. Photons that enter these nanoscale funhouses bounce back and forth up to 10,000 times, greatly enhancing their chance of interacting with the electrons in the NV center. This increases the efficiency of information transfer between photons and the NV center’s electron spin state.

    The devices’ performance was characterized in part using optical microscopy in a magnetic field at the CFN, performed by CFN staff scientist Mircea Cotlet, Luozhou Li, and Edward Chen, who is also a graduate student studying under the guidance of Englund at MIT.

    4
    Brookhaven scientist Mircea Cotlet at the CFN, where he and the MIT graduate students performed optical measurements of the quantum memory devices.

    “Coupling the NV centers with these optical resonator cavities seemed to preserve the NV spin coherence time—the duration of the memory,” Cotlet said.

    Added Englund: “These methods have given us a great starting point for translating information between the spin states of the electrons among multiple NV centers. These results are an important part of validating the scientific promise of NV-cavity systems for quantum networking.”

    In addition, said Li, “The transferred hard mask lithography technique that we have developed in this work would benefit most unconventional substrates that aren’t suitable for typical high-resolution patterning by electron beam lithography. In our case, we overcame the problem that hundred-nanometer-thick diamond membranes are too small and too uneven. ”
    Ming Lu

    6
    CFN staff scientist Ming Lu helped to fabricate diamond-and-air layered nanoscale “funhouses” that trap light so it can interact with atomic spin states.

    The methods may also enable the long-distance transfer of quantum-encoded information over fiber optic cables. Such information could be made completely secure, Englund said, because any attempt to intercept or measure the transferred information would alter the photons’ properties, thus alerting the sender and the recipient to the possible presence of an eavesdropper.

    Fabrication and experiments were supported in part by the Air Force Office of Scientific Research. The CFN at Brookhaven Lab is supported by the DOE Office of Science. Additional funding for individual researchers came from the Alexander von Humboldt Foundation, the NASA Office of the Chief Technologist’s Space Technology Research Fellowship, and the National Science Foundation.

    Working Together: Benefits for Facility Users, Students, and CFN

    “At the CFN,” said longtime facility user Dirk Englund of MIT, “we can do things that are very difficult or impossible in a normal university setting. Developing a radically new process, like our processing of diamond quantum memories, has been so successful at the CFN because of the consistency in the fabrication tools, the wide range of characterization tools, and the expert knowledge.”

    His students agree: “We got a lot of technical support and scientific guidance from CFN research scientists, who are willing to help early-year students start their research careers,” said MIT graduate student Luozhou Li. In addition, he said, “CFN has all the advanced nanofabrication and confocal facilities centralized in one place. It is convenient and efficient to step from one room to another, finish the device fabrication in a clean-room environment and measure optical properties quickly.”

    Edward Chen, the other MIT grad student involved in this work, appreciated the chance to see first-hand the benefits of working in an interdisciplinary atmosphere at Brookhaven Lab, where state-of-the-art facilities like the CFN and the new National Synchrotron Light Source II (NSLS-II) can be found side-by-side. “I hope to continue finding ways to improve the nanofabrication process we developed for this research so that I can potentially take advantage of other unique facilities available at Brookhaven Lab,” he said.

    The benefits go both ways, said CFN staff scientist, Mircea Cotlet. “We now have a new method we can use and pass on to future users,” he said, referring to the electron spin resonance microscopy techniques used to measure the spin-dependent fluorescence of the NV centers and resonators explored in this study.

    On a more personal note, Cotlet added, “I have never worked with such challenging students.” The collaboration, he said, helped invigorate his work. “I learned a lot from them. They make you realize you don’t have all the answers.”

    Continuing to stimulate that kind of intellectual interaction for the benefit of science and society is what research at DOE user facilities like the CFN is all about.

    See the full article here.

    BNL Center for Functional Nanomaterials
    BNL Center for Functional Nanomaterials

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    BNL Campus

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

     
  • richardmitnick 9:07 pm on September 18, 2013 Permalink | Reply
    Tags: , BNL CFN, , , ,   

    From Brookhaven Lab: “Nanocrystal Catalyst Transforms Impure Hydrogen into Electricity” 

    Brookhaven Lab

    Brookhaven Lab scientists use simple, ‘green’ process to create novel core-shell catalyst that tolerates carbon monoxide in fuel cells and opens new, inexpensive pathways for zero-emission vehicles

    September 18, 2013
    Contacts: Justin Eure, (631) 344-2347 or Peter Genzer, (631) 344-3174

    The quest to harness hydrogen as the clean-burning fuel of the future demands the perfect catalysts—nanoscale machines that enhance chemical reactions. Scientists must tweak atomic structures to achieve an optimum balance of reactivity, durability, and industrial-scale synthesis. In an emerging catalysis frontier, scientists also seek nanoparticles tolerant to carbon monoxide, a poisoning impurity in hydrogen derived from natural gas. This impure fuel—40 percent less expensive than the pure hydrogen produced from water—remains largely untapped.

    “Our highly scalable, ‘green’ synthesis method, as revealed by atomic-scale imaging techniques, opens new and exciting possibilities for catalysis and sustainability.”
    — Brookhaven Lab Chemist Jia Wang

    team
    Brookhaven Lab scientists Radoslav Adzic, Vyacheslov Volcov, Lijun Wu (back), Wei An, Jia Wang, and Dong Su (front) gathered in the control room for a scanning transmission electron microscope (STEM) in the Center for Functional Nanomaterials.

    Now, scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory—in research published online September 18, 2013 in the journal Nature Communications—have created a high-performing nanocatalyst that meets all these demands. The novel core-shell structure—ruthenium coated with platinum—resists damage from carbon monoxide as it drives the energetic reactions central to electric vehicle fuel cells and similar technologies.

    “These nanoparticles exhibit perfect atomic ordering in both the ruthenium and platinum, overcoming structural defects that previously crippled carbon monoxide-tolerant catalysts,” said study coauthor and Brookhaven Lab chemist Jia Wang. “Our highly scalable, ‘green’ synthesis method, as revealed by atomic-scale imaging techniques, opens new and exciting possibilities for catalysis and sustainability.”

    Scientists at Brookhaven Lab’s National Synchrotron Light Source (NSLS) revealed the atomic density, distribution, and uniformity of the metals in the nanocatalysts using a technique called x-ray diffraction, where high-frequency light scatters and bends after interacting with individual atoms. The collaboration also used a scanning transmission electron microscope (STEM) at Brookhaven’s Center for Functional Nanomaterials (CFN) to pinpoint the different sub-nanometer atomic patterns. With this instrument, a focused beam of electrons bombarded the particles, creating a map of both the core and shell structures.

    “We found that the elements did not mix at the core-shell boundary, which is a critical stride,” said CFN physicist Dong Su, coauthor and STEM specialist. “The atomic ordering in each element, coupled with the right theoretical models, tells us about how and why the new nanocatalyst works its magic.”

    See the full article here.

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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