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• Magnetic field assisted nanoparticle dispersion
  Posted by Johan Martens
  B. Stuyven, Q. Chen, W. Van de Moortel, H. Lipkens, B.Caerts, A. Aerts, L. Giebeler, B. Van Eerdenbrugh, P. Augustijns. G. Van den Mooter, J. Van Humbeeck, J. Vanacken, V. Moshchalkov, J. Vermant en J. A. Martens
  Magnetohydrodynamic nanoparticle dispersion is an energy efficient method to deaggregate nanoparticles, combining hydrodynamic forces of turbulent flow with Lorentz forces generated by a magnetic field.
  
  
  
  
  

• Confinement of surface state electrons in self-organized Co islands on Au(111)
  Posted by Peter Lievens
  Koen Schouteden, Erwin Lijnen, Ewald Janssens, Arnout Ceulemans, Liviu F Chibotaru, Peter Lievens and Chris Van Haesendonck
  We report on detailed low temperature scanning tunneling spectroscopy measurements performed on nanoscale Co islands on Au(111) films. At low coverages, Co islands self-organize in arrays of mono- and bilayer nanoscale structures that often have an hexagonal shape. The process of self-organization is induced by the Au(111) 'herringbone' reconstruction. By means of mapping of the local density of states with lock-in detection, electron standing wave patterns are resolved on top of the atomically flat Co islands. The surface state electrons are observed to be strongly confined laterally inside the Co nanosized islands, with their wavefunctions reflecting the symmetry of the islands. To complement the experimental work, particle-in-a-box calculations were performed. The calculations are based on a newly developed variational method that can be applied to '2D boxes' of arbitrary polygonal shape. The experimental patterns are found to fit nicely to the calculated wavefunctions for a box having a symmetry corresponding to the experimental island symmetry. The small size of the Co islands under study (down to 7.7 nm2) is observed to induce a strong discretization of the energy levels, with very large energy separations between the eigenstates up to several 100 meV. The observed standing wave patterns are identified either as individual eigenstates or as a 'mixture' of two or more energetically close-lying eigenstates of the cobalt island. Additionally, the Co surface state appears not to be limited to mono- and bilayer islands, but this state remains observable for multilayered islands up to five monolayers of Co.
  
  
  

• Antiferromagnetic LaFeO3 thin films and their effect on exchange bias
  Posted by Jean-Pierre Locquet
  JW Seo, EE Fullerton, F. Nolting, A Scholl, J Fompeyrine and JP Locquet
  LaFeO3 in antiferromagnet with a very high Neel temperature (740K) and is a model system to study the magnetic coupling between antiferromagnets and adjacent ferromagnets. In this review paper the growth, structural and magnetic properties of LaFeO3 thin films and their exchange coupling with different ferromagnetic layers are reported.
  
  
  

External news feeds

• Advance in nanotech gene sequencing technique
  

  (Phys.org) —The allure of personalized medicine has made new, more efficient ways of sequencing genes a top research priority. One promising technique involves reading DNA bases using changes in electrical current as they are threaded through a nanoscopic hole.

• Faster, stronger, lighter: New technique advances carbon-fiber composites
  

  These days, aerospace engineering is all about the light stuff: building airplanes with lighter wings, fuselage and landing gear in an effort to reduce fuel costs.

• Engineers' nanoantennas improve infrared sensing
  

  (Phys.org) —A team of University of Pennsylvania engineers has used a pattern of nanoantennas to develop a new way of turning infrared light into mechanical action, opening the door to more sensitive infrared cameras and more compact chemical-analysis techniques.

• Kinks and curves at the nanoscale
  

  One of the basic principles of nanotechnology is that when you make things extremely small—one nanometer is about five atoms wide, 100,000 times smaller than the diameter of a human hair—they are going to become more perfect.

• How nanotechnology could keep your heart healthy
  

  Since the heart is such a delicate and critical organ, clinicians usually opt not to intervene with the dead cells that remain after a heart attack or cardiac disease. "But we think that all heart attacks deserve some kind of treatment because it puts so much stress on the rest of the heart," said Thomas Webster, professor and chair of the Department of Chemical Engineering. Even a square centimeter of dead heart tissue can put significant strain on the rest of the heart, which has to pick up the slack, he said.

• Research improves dry lubricant used in machinery and biomedical devices
  

  Nearly everyone is familiar with the polytetrafluoroethylene (PTFE), otherwise known as Teflon, the brand name used by the chemical company DuPont. Famous for being "non-sticky" and water repellent, PTFE is a dry lubricant used on machine components everywhere, from kitchen tools and engine cylinders to space and biomedical applications.

• Stacking 2-D materials produces surprising results
  

  (Phys.org) —Graphene has dazzled scientists, ever since its discovery more than a decade ago, with its unequalled electronic properties, its strength and its light weight. But one long-sought goal has proved elusive: how to engineer into graphene a property called a band gap, which would be necessary to use the material to make transistors and other electronic devices.

• Graphene-boron mix shows promise for lithium-ion batteries
  

  Frustration led to revelation when Rice University scientists determined how graphene might be made useful for high-capacity batteries.

• Researchers report first fully integrated artificial photosynthesis nanosystem
  

  (Phys.org) —In the wake of the sobering news that atmospheric carbon dioxide is now at its highest level in at least three million years, an important advance in the race to develop carbon-neutral renewable energy sources has been achieved. Scientists with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) have reported the first fully integrated nanosystem for artificial photosynthesis. While "artificial leaf" is the popular term for such a system, the key to this success was an "artificial forest."

• DNA-guided assembly yields novel ribbon-like nanostructures
  

  (Phys.org) —Scientists at the U.S. Department of Energy's Brookhaven National Laboratory have discovered that DNA "linker" strands coax nano-sized rods to line up in way unlike any other spontaneous arrangement of rod-shaped objects. The arrangement-with the rods forming "rungs" on ladder-like ribbons linked by multiple DNA strands-results from the collective interactions of the flexible DNA tethers and may be unique to the nanoscale. The research, described in a paper published online in ACS Nano, a journal of the American Chemical Society, could result in the fabrication of new nanostructured materials with desired properties.

• Snake's ultra-black spots may aid high-tech quest
  

  Scientists have identified nanostructures in the ultra-black skin markings of an African viper which they said Thursday could inspire the quest to create the ultimate light-absorbing material.

• Carbon in a twirl: The science behind a self-assembled nano-carbon helix
  

  Nanotechnology draws on the fabrication of nanostructures. Scientists have now succeeded in growing a unique carbon structure at the nanoscale that resembles a tiny twirled mustache. Their method might lead the way to the formation of more complex nano-networks. Researchers of the Electronic Properties of Materials Group at the Faculty of Physics (University of Vienna) and their international collaborators have published their results in the new open-access journal of the Nature Publishing group, Scientific Reports.

• Moth-inspired nanostructures take the color out of thin films
  

  Inspired by the structure of moth eyes, researchers at North Carolina State University have developed nanostructures that limit reflection at the interfaces where two thin films meet, suppressing the "thin-film interference" phenomenon commonly observed in nature. This can potentially improve the efficiency of thin-film solar cells and other optoelectronic devices.

• Nanotechnology could help fight diabetes: Injectable nanogel can monitor blood-sugar levels, secrete insulin when needed
  

  Injectable nanoparticles developed at MIT may someday eliminate the need for patients with Type 1 diabetes to constantly monitor their blood-sugar levels and inject themselves with insulin.

• Ultraresponsive magnetic nanoscavengers for next generation water purification
  

  (Phys.org) —Among its many talents, silver is an antibiotic. Titanium dioxide is known to glom on to certain heavy metals and pollutants. Yet other materials do the same for salt. In recent years, environmental engineers have sought to disinfect, depollute, and desalinate contaminated water using nanoscale particles of these active materials. Engineers call them nanoscavengers. The hitch from a technical standpoint is that it is nearly impossible to reclaim the nanoscavengers once in the water.

• 40-year-old prediction confirmed: First direct proof of Hofstadter butterfly fractal observed in moire superlattices
  

  A team of researchers from Columbia University, City University of New York, the University of Central Florida (UCF), and Tohoku University and the National Institute for Materials Science in Japan, have directly observed a rare quantum effect that produces a repeating butterfly-shaped energy spectrum, confirming the longstanding prediction of this quantum fractal energy structure, called Hofstadter's butterfly. The study, which focused on moiré-patterned graphene, is published in the May 15, 2013, Advance Online Publication (AOP) of Nature.

• Catching graphene butterflies
  

  Writing in Nature, a large international team led Dr Roman Gorbachev from The University of Manchester shows that, when graphene placed on top of insulating boron nitride, or 'white graphene', the electronic properties of graphene change dramatically revealing a pattern resembling a butterfly.

• Physicists discover a new kind of friction in the nanoworld
  

  Whether in vehicle transmissions, hip replacements, or tiny sensors for triggering airbags: The respective components must slide against each other with minimum friction to prevent loss of energy and material wear. Investigating the friction behavior of nanosystems, scientists from the Technische Universitaet Muenchen have discovered a previously unknown type of friction that sheds new light on some previously unexplainable phenomena.

• Squishy hydrogels may be the ticket for studying biological effects of nanoparticles
  

  (Phys.org) —A class of water-loving, jelly-like materials with uses ranges ranging from the mundane, such as superabsorbent diaper liners, to the sophisticated, such as soft contact lenses, could be tapped for a new line of serious work: testing the biological effects of nanoparticles now being eyed for a large variety of uses.

• Scientists discovering new uses for tiny carbon nanotubes
  

  Nanotubes are stronger than steel and smaller than any element of silicon-based electronics. They can potentially process information faster while using less energy. The challenge has been figuring out how to incorporate these properties into useful electronic devices. Now scientists at the University of California, Riverside have discovered that by adding ionic liquid—a kind of liquid salt—they can modify the optical transparency of single-walled carbon nanotube films in a controlled pattern.

• Chemists demonstrate nanoscale alloys so bright they could have potential medical applications
  

  (Phys.org) —Alloys like bronze and steel have been transformational for centuries, yielding top-of-the-line machines necessary for industry. As scientists move toward nanotechnology, however, the focus has shifted toward creating alloys at the nanometer scale—producing materials with properties unlike their predecessors.

• Microgravity experiment gets funding, may go to International Space Station
  

  A microgravity experiment designed at The Methodist Hospital Research Institute will be funded by The Center for the Advancement of Science in Space (CASIS) to fly aboard the International Space Station U.S. National Laboratory.

• Researchers develop synthetic HDL cholesterol nanoparticles
  

  (Phys.org) —Atherosclerosis, a buildup of cellular plaque in the arteries, remains one of the leading causes of death globally. While high-density lipoprotein, or HDL, the so-called good cholesterol, is transferred to the liver for processing, low-density lipoprotein, or LDL, builds up in the arteries in the form of plaque.

• Bovine blood keeps gold nanoparticles stable
  

  (Phys.org) —A protein from cow blood has the remarkable ability to keep gold nanoparticles from clumping in a solution. The discovery could lead to improved biomedical applications and contribute to projects that use nanoparticles in harsh environments.

• Solar panels as inexpensive as paint? It's possible due to new research
  

  (Phys.org) —Most Americans want the U.S. to place more emphasis on developing solar power, recent polls suggest. A major impediment, however, is the cost to manufacture, install and maintain solar panels. Simply put, most people and businesses cannot afford to place them on their rooftops.

• Team observes real-time charging of a lithium-air battery
  

  One of the most promising new kinds of battery to power electric cars is called a lithium-air battery, which could store up to four times as much energy per pound as today's best lithium-ion batteries. But progress has been slow: The nature of the electrochemical reactions as these batteries are charged remains poorly understood.

• New insight into early growth of solid thin films
  

  (Phys.org) —The foundation of many modern electronic devices, such as computer chips, are thin films – nanoscale-thickness layers of one material grown on the surface of another. As consumers continue to demand products that are sleeker and faster, understanding the evolution of thin-film growth will help scientists learn to tailor thin films for new technologies.

• How to overcome the oxide barrier
  

  (Phys.org) —Researchers at Pacific Northwest National Laboratory have uncovered the characteristics of a low-resistance electrical contact to strontium titanate, SrTiO3, an important prototypical oxide semiconductor. Oxides are likely to be important materials in next-generation electronic devices, and they need to be extremely small. Getting electrical signals into and out of oxide semiconductors is hard because a large energy barrier typically develops at the junction with metal contacts. Metal contacts are required to get electricity into and out of a semiconductor device in much the same way that jumper cables are needed to transfer power from a healthy car battery to a dead battery. This work shows how to eliminate this barrier while keeping the contact area extremely small, at the nanometer level.

• Graphene joins the race to redefine the ampere
  

  A new joint innovation by the National Physical Laboratory (NPL) and the University of Cambridge could pave the way for redefining the ampere in terms of fundamental constants of physics. The world's first graphene single-electron pump (SEP), described in a paper today in Nature Nanotechnology, provides the speed of electron flow needed to create a new standard for electrical current based on electron charge.

• Nano-breakthrough: Solving the case of the herringbone crystal
  

  Leading nanoscientists created beautiful, tiled patterns with flat nanocrystals, but they were left with a mystery: Why did some sets of crystals arrange themselves in an alternating, herringbone style? To find out, they turned to experts in computer simulation at the University of Michigan and the Massachusetts Institute of Technology.