Physics News Update Number 689, June 21, 2004

From: Sam Wormley (swormley1_at_mchsi.com)
Date: 06/22/04 

Date: Tue, 22 Jun 2004 00:53:42 GMT

Ref: http://www.aip.org/pnu/2004/689.html
Physics News Update Number 689, June 21, 2004
by Phil Schewe and Ben Stein

Nanotube Water

  Nanotube water, a one-dimensional form of water consisting of a
  string of water molecules confined in a carbon nanotube, has been
  studied with neutron scattering by physicists at Argonne National
  Lab. Neutron scattering measurements, along with computer simulations
  of the molecular interactions between the water and the surrounding
  single-walled carbon nanotube, confirmed that water molecules had
  successfully been taken up into the nanotubes in the form of a
  "wire." But this was not all; surrounding the water wire was another
  water structure, a sheath of water, a cylindrical square-ice- sheet
  formation (see figure).

  The result of this novel architecture was that fluid-like behavior
  was observed at temperatures far below the freezing point of normal
  water. The hydrogen bonds along the water chain seem to be softened,
  allowing, for example, a freer movement of protons along the chain.
  The Argonne researchers (contact Alexander Kolesnikov,
  akolesnikov@anl.gov, 630-252-3555) believe that this anomalous
  behavior might help to explain other phenomena featuring nm-scale
  confined water such as water migration from soil to plants via xylem
  vessels and the proton translocation in transmembrane proteins.
  (Kolesnikov et al., Physical Review Letters, upcoming article)

Amorphous Steel

  Amorphous steel, long a goal of metallurgists, has been fabricated
  for the first time by scientists at Oak Ridge National Lab. The
  amorphous steel produced has a hardness and strength more than twice
  that of the best ultra-high-strength conventional steel. Some
  amorphous (glassy) iron-based alloys have been employed in making
  transformer cores, the electrical devices which transform electricity
  from one voltage to another, and have reduced energy losses thereby
  by two-thirds. But not until now has glassy steel of the kind used in
  building structures been made.

  Steel, an alloy of mostly iron atoms with varying amounts of carbon
  and other elements, is ordinarily a crystal, with an internal
  structure consisting of neat rows of atoms. If produced quickly from
  a liquid phase, however, a disordered solid can result. The trick is
  to find conditions---including the chemical content of the alloy,
  such as the addition of yttrium in this case---that favor the liquid
  phase and frustrate the onset of crystallization even as the
  solidification temperature is approached.

  The researchers (Zhou Ping Lu, 865-576-7196, luzp@ornl.gov) have
  produced centimeter-sized pieces of the amorphous steel, and they
  feel that structural steel in bulk metallic glass form can be
  produced economically with traditional drop-casting methods, in which
  metallic glasses are made by pouring the hot liquid into a cold
  copper mold. (Lu et al., Physical Review Letters, 18 June 2004)

Nanoimprint Lithography

  Nanoimprint lithography featuring line widths of only 16 nm and a
  line spacing of 14 nm has been achieved by scientists at Princeton
  University. Sustaining this delicate work of fine patterning and
  fabrication, furthermore, was sustained across the face of 4-inch
  wafer.

  One way to increase the density of storable data or computing power
  of microchips is of course to shrink the circuitry, but new
  difficulties arise when the size or spacing of lines gets too small.
  Getting below a 35-nm pitch, for example, is difficult when using an
  electron beam to do the lithography.

  Therefore the Princeton researchers used "photocurable nanoimprint
  lithography" (P-NIL), a process in which a mold is pressed into a
  resist medium which is then cured with ultraviolet rays. After this
  the resist is etched away, leaving behind thin 5-nm-wide polymer
  walls. Gold contacts 5 nm apart can also be fabricated. (Austin et
  al., Applied Physics Letters, 28 June 2004)

Earth's Oceanic Currents and Jupiter's Bands

  Earth's oceanic currents and Jupiter's bands bear a certain
  resemblance to each other, a new report suggests. The work consists
  of comparisons of the stripes visible in Jupiter's upper atmosphere
  and zones of water at a depth of 1000 meters stretching across the
  Pacific Ocean on Earth. The gas jets on Jupiter and the ocean
  currents on Earth not only look alike, but the energy spectra of each
  are characterized by a downward sloping "power law" curve; that is,
  the likelihood of jets of a certain size is proportional to the size
  raised to a power. The oceanographers working on this study
  themselves stretch halfway across the world, coming from the
  University of South Florida (US), the Meteorological Research
  Institute (Japan), Columbia University (US), and the Ben-Gurion
  University (Israel). (Galperin et al., Geophysical Research Letters,
  June 2004)

Physics News Update is a digest of physics news items arising from
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