NANOSCALE PHYSICS LABORATORY COMES ONLINE.A new nanoscale physics laboratory was recently commissioned by NIST (National Institute of Standards & Technology, Washington, DC, www.nist.gov) The standards-defining agency of the U.S. government, formerly the National Bureau of Standards. It is one of three agencies that fall under the Technology Administration (www.technology. researchers to support the development of new measurement methods for future nanotechnologies. This laboratory establishes a new state-of-the-art for nanostructure fabrication and measurement and positions NIST to be a major contributor in this rapidly emerging nanotechnology arena. The laboratory will be used to fabricate electronic and magnetic nanostructures and measure their physical properties with atomic-scale resolution. Current research is focused on quantum and spin electronics, areas central to the emerging nanotechnology revolution. The laboratory came online with the successful operation of the main measurement system, a scanning tunneling microscope scanning tunneling microscope, device for studying and imaging individual atoms on the surfaces of materials. The instrument was invented in the early 1980s by Gerd Binnig and Heinrich Rohrer, who were awarded the 1986 Nobel prize in physics for their work. (STM (Scanning Tunneling Microscope) A microscope that can image down to the atomic level. An STM uses a piezoelectric tube with a tiny sharp tip at the end that is moved within nanometers of the object being sampled. ) operating at cryogenic temperatures in an intense magnetic field. The cryogenic STM was designed and built at NIST. Novel features of the microscope include a solid molybdenum molybdenum (məlĭb`dənəm) [Gr.,=leadlike], metallic chemical element; symbol Mo; at. no. 42; at. wt. 95.94; m.p. about 2,617°C;; b.p. about 4,612°C;; sp. gr. 10.22 at 20°C;; valence +2, +3, +4, +5, or +6. body design (made possible by the high-speed machining capabilities at NIST), an integral three-axes positioning system of the sample and tip with picometer precision, optical access to the sample/tip junction, and non-magnetic construction. The microscope is a completely self-contained unit that can be translated between a room-temperature system and a liquid He cryostat cryostat /cryo·stat/ (kri´o-stat) 1. a device by which temperature can be maintained at a very low level. 2. in pathology and histology, a chamber containing a microtome for sectioning frozen tissue. . The microscope was designed to have very high spatial and energy resolution. It can measure displacements below 1 pm and resolve electron energy levels separated by 600 [micro]V. Operating in cryogenic, high-magnetic field, and ultra-high vacuum environments, the microscope measures electronic and magnetic properties of nanostructures on an atom-by-atom basis. The microscope has achieved atomic resolution measurements on the surface of Cu(111) at 2.3 K and in magnetic fields up to 10 T. The stability of the microscope allows atomic resolution measurements to remain in registry while the magnetic field is swept. The laboratory contains facilities for the fabrication of samples, tips, and nanostructures. The facilities include traditional molecular beam epitaxy A technique that "grows" atomic-sized layers on a chip rather than creating layers by diffusion. of III-V semiconductors, superconductors, and magnetic materials, as well as bottom-up nanofabrication nan·o·fab·ri·ca·tion n. Any technique used to create objects or mechanisms on the scale of nanotechnology. using autonomous atom assembly. |
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