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May 15, 2008 :: Northwestern University

Plasmonic Properties of Aluminum Nanoparticles Fabricated by Nanosphere Lithography [Research]

Recent work at the Northwestern University MRSEC has shown that aluminum nanoparticles fabricated using a process known as nanosphere lithography (NSL) display plasmons throughout the UV-vis region.

May 15, 2008 :: Northwestern University

Detection of Single Gold Atoms in Silicon Nanowires [Research]

Semiconductor nanowires grown with metal nanocatalysts are new materials that provide a basis for transformative improvements in diverse technologies including thermoelectrics and photovoltaics.

May 2, 2008 :: University of Massachusetts Amherst

Chip Breakthrough Technology [Research]

umass1.jpgA collaboration between researcher supported by the DOE and NSF-MRSEC’s at UC Santa Barbara and UMASS Amherst, and IBM has led to a revolutionary chip breakthrough that promises to be used in every future microelectronic device.

May 1, 2008 :: Cornell University

Graphene Membranes: Atomically Thin Balloons [Research]

Membranes are fundamental components of a wide variety of physical, chemical, and biological systems. They divide space into two regions, each capable of possessing different physical or chemical properties. A simple example is the stretched surface of a balloon, where a pressure difference across the balloon is balanced by the surface tension in the membrane. The thinnest imaginable balloon would be one atom thick. Cornell researchers have shown that one-atom-thick graphene membranes act like a nano-balloon. In spite of their thinness, they are impermeable to gases and can support pressure differences larger than one atmosphere. Such pressure differences cause the membranes to bend like the surface of a balloon, as shown in the figure. Single-atom-thick membranes offer great promise for certain types of microscopy that can peer through the membrane into the trapped region.  J. S. Bunch, S. S. Verbridge, J. S. Alden, A. van der Zande, J. M. Parpia, H. G. Craighead, P. L. McEuen, “Impermeable atomic membranes from graphene sheets,” submitted (2007).

May 1, 2008 :: Cornell University

Studying a Single-Atom Magnet [Research]

Researchers at Cornell University are trying to understand the subtle interactions between magnetic materials and electrical currents by interrogating the smallest magnet possible — a single atom. In their experiments, a single magnetic nitrogen atom (blue in the diagram) is first trapped in a protective cage made of 60 carbon atoms (C60, black in diagram). The cage is then suspended between two tiny platinum electrodes. The scientists probe the response of the caged atom to electrical currents and magnetic fields. By watching single electrons hop on and off the system as a magnetic field is applied, the magnetic properties of the molecule can be quantified and controlled.  Single magnetic molecules such as the one studied here may enable new types of high-density information storage (e.g., magnetic computer memory) or a new class of ultrasmall, but extremely powerful, computers (so-called “quantum computers”). This experiment shows that single molecule magnets can be put into electronic devices and controlled — the first step towards the new technology.<br /> J. E. Grose, E. S. Tam, C. Timm, M. Scheloske, B. Ulgut, J. J. Parks, H. D. Abruña, W. Harneit, and D. C. Ralph, “Tunneling spectra of individual magnetic endofullerene molecules” (submitted).

April 21, 2008 :: University of California at Santa Barbara

Squid Beaks use Novel Materials Trick to keep from Tearing Off [Research]

squid.jpg Researchers have figured out how a jumbo squid’s hard, razor-sharp beak can slice through the soft tissue of its prey–without tearing off from the stress. The work solves a longstanding mystery over a problem akin to anchoring a knife blade in Jell-O, according to the authors of the new study.

April 21, 2008 :: University of California at Santa Barbara

Traveling Display Booth for Promotion of the Materials Research Facilities Network [Facilities]

mrfnbooth2.jpgFor the first time, a traveling exhibit promoting the MRSEC program and the Materials Research Facilities Network was presented at the 2008 NOBCChE (National Organization of Chemists and Chemical Engineers) meeting in Philadelphia.

April 7, 2008 :: University of Chicago

Self-Assembled Nanocrystal Membranes [Research]

nanomembraneClose-packed nanocrystal monolayers can be self-assembled by simple drop casting into ultra-thin free-standing membranes. Researchers at the University of Chicago MRSEC have shown that these membranes are remarkably strong, with a Young’s modulus on the order of several GPa, yet highly flexible. The arrays remain intact and able to withstand tensile stresses up to temperatures around 370K. The purely elastic response of these membranes, coupled with exceptional robustness and resilience at elevated temperatures makes them excellent candidates for a wide range of sensor applications.