Embargoed until 2 p.m. EST
NSF PR 01-17 - March 7, 2001
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Superconductivity: Making it Work in the Real World
Scientists have confirmed it: a common compound has
profound potential for future uses.
Excitement has built as scientists raced to analyze
the properties of a new high-temperature superconductor
found in January by a Japanese team in a simple, commonly
available compound.
Now, U.S. materials researchers have explored whether
the compound, magnesium diboride or MgB2,
will be useful for real-world applications such as
electronics, communications and industrial tasks that
would benefit from the passage of large amounts of
current with no resistance. A team at a National Science
Foundation (NSF) materials research center at the
University of Wisconsin, in collaboration with an
NSF-funded solid-state chemistry group at Princeton
University, demonstrate in the March 8 issue of Nature
that the answer is "yes."
"We've confirmed that this readily available compound
has the special capabilities needed for the frictionless
conduction of electricity, laying the groundwork for
its potential use," said David Larbalestier of NSF's
Materials Research Science and Engineering Center
for Nanostructured Materials and Interfaces, located
at the University of Wisconsin at Madison.
Superconductors are materials that lose all their resistance
to electrical current flow below a certain critical
temperature. The higher the critical temperature,
the more useful the material for practical applications.
Magnesium diboride's critical temperature at 39 Kelvin
is lower than other candidate materials--generally
copper oxides--but has other properties that this
team says make it a "go."
In the copper oxide superconductors discovered so far,
the interfaces between the crystals of the material--the
so-called "grain boundaries"--interfere with the efficient
flow of current, severely limiting their usefulness.
Larbalestier's team showed that this is not the case
in magnesium diboride. Instead, the current passes
smoothly between the crystal grains. The team tested
the material in strong magnetic fields to determine
that this beneficial quality pervades its entire structure.
"One of the unfulfilled promises of previously known
copper-oxide superconductors is the commercial production
of wires carrying large amounts of current for everyday
applications," said Robert Cava of Princeton University.
"The process of making a newly discovered superconductor
into wires or other practical devices can take years.
In this paper we report the first steps." Potential
applications include magnetic resonance imaging (MRI)
devices, more efficient power transmission lines and
a variety of electronic devices.
Cava said the scientists, some of whom have worked
on the properties of high-temperature superconductors
for well over a decade, are "very excited" that their
students have had the opportunity to work on such
an important discovery.
The Wisconsin materials center is one of NSF's 29 multidisciplinary
facilities working on different aspects of materials
science. Education and research experiences for students
are an important goal of the centers.
For more information on the materials research center,
see http://mrsec.wisc.edu/
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