|
Stripe
Formation. Picture of the spin
and charge densities in the copper-oxygen
planes where the conducting electrons
are located. Lower density antiferromagnetic
regions are seen to alternate
with higher charge density regions.
Such an effect is far more probable
in two dimensional, i.e., planar,
geometrical arrangements. |
Since the discovery in the 1980s
of high-temperature superconductors,
the Office of Science has supported
research designed to explain and improve
the physical behavior of these materials
and develop methods of making wires
and other objects from them. These
materials conduct electricity with
virtually no resistance at temperatures
high enough to be cooled by liquid
nitrogen (-196 degrees C, or -321
degrees F) instead of more costly
helium. Studies at various national
laboratories have led to discoveries
concerning, for example, the relationships
between magnetic behavior and superconductivity,
and between material layering and
current-carrying capability. Argonne
National Laboratory clarified the
nature of several different phases
of vortex matter (compounds often
break down at the vortex, where the
molecules of different materials meet),
leading to new configurations that
improve conductivity. Argonne also
built the first superconducting motor
and developed a process for welding
lengths of wire in a way that maintains
superconductivity. Other investigators
have observed "charge stripes" in
materials exhibiting colossal magnetoresistance,
an unusual and powerful effect that
may be exploited in future magnetic
recording devices. Years of research
at Oak Ridge National Laboratory led
to the development of processes that
may enable the manufacture of long
lengths of superconducting wires and
tape.
Scientific Impact:
This research has greatly increased
scientific understanding of high-temperature
superconductors. As yet, there is
no comprehensive theory that explains
all of the experimental phenomena;
this remains a key question in condensed
matter physics.
Social Impact: Superconducting
wires and tape can carry 100 to 200
times more electric current than conventional
wires. These innovations could enable
the widespread commercialization of
more efficient types of power generation,
transmission, and electrical equipment
and devices, offering tremendous energy
savings and emissions reductions.
Reference: S.L.
Bud'ko, G. Lapertot, C. Petrovic,
C.E. Cunningham, N. anderson, and
P.C. Canfield. "Boron Isotope Effect
in Superconducting MgB2," Physical
Review Letters, February 26,
2001.
URL: http://www.external.ameslab.gov/news/release/superconducting.htm
http://www.msd.anl.gov/groups/sm/decades.htm
http://www.ms.ornl.gov/sections/ms/ms.htm
http://www.ma.doe.gov/energy100/future/48.html
http://www.osti.gov/sup/suphome.html
Technical Contact:
Don Freeburn, Office of Basic Energy
Sciences, 301-903-3156
Press Contact: Jeff
Sherwood, DOE Office of Public Affairs,
202-586-5806
SC-Funding Office:
Office of Basic Energy Sciences |