superconductor

From: xgl (xli03@emory.edu)
Date: Sun Feb 25 2001 - 11:57:35 MST


        can't believe they are still using farenheit.

-x

---------- Forwarded message ----------
Date: Fri, 23 Feb 2001 22:40:01 PST
From: "AP / MALCOLM RITTER, AP Science Writer" <C-ap@clari.net>
Subject: New Discovery May Impact Computers

                                             
        In a startling result, scientists have found that a common metal
compound can carry electricity with virtually no resistance at a
higher temperature than previously thought possible. The compound
might become useful for building superfast computers.
        Two labs report that the magnesium-boron compound becomes
``superconducting'' at temperatures of around minus 388 degrees to
minus 389 degrees. That is still mighty cold, but it is warmer than
the previous record for simple metallic compounds of about minus
418.
        Since superconducting compounds must be chilled to work,
scientists are eager to find materials that work at higher, more
easily attained temperatures.
        The new work will be reported in next Thursday's issue of the
journal Nature by Jun Akimitsu of the Aoyama-Gakuin University in
Tokyo with colleagues, and in next Monday's issue of Physical
Review Letters by Paul Canfield and colleagues at the Ames
Laboratory and the department of physics and astronomy at Iowa
State University. Canfield's group followed up on Akimitsu's work.
        The Japanese work was startling because the superconductivity
temperature was so much higher than ever observed in such metallic
compounds, Robert Cava of Princeton University wrote in a Nature
commentary.
        ``The field of superconductivity has been rocked'' by the news,
he said.
        Cava said superconductivity researchers have virtually ignored
such simple metallic compounds for 15 years in favor of a class of
oxygen-containing materials, which superconduct at much higher
temperatures than even the newly reported compound, up to minus 172
degrees.
        Some experts said the magnesium-boron compound might pay off in
making very fast computer components, where the oxygen-containing
materials have proven hard to work with.
        John Rowell, a professor in materials science at Northwestern
University, said scientists have done much work with
lower-temperature materials like the metallic element niobium. If
the magnesium-boron material could be used instead, the components
might work as much as four times faster because of the higher
superconducting temperature, he said.
        He noted that it is not clear whether the overall idea of
superconducting electronics will prove useful in computers.
        Ted Geballe, a superconductivity expert at Stanford University,
said he gives the magnesium-boron material an outside chance of
becoming useful in electronics, but he added that ``it's so new
it's worth looking at.''
        Cava, in his commentary, said superconducting materials based on
the compound might one day be able to carry more current than wires
made from the oxygen-bearing materials. Scientists hope
superconducting wire will be able to routinely carry electricity
without substantial losses to resistance.
                     



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