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Organic
superconductor with the highest
Tc k-(ET)2Cu[N(CN)2]Cl
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Superconductors conduct electricity
with little or no resistance. Organic
superconductors contain carbon and
are less dense than their ceramic
or metallic counterparts; they also
offer unusual potential for fine-tuning
of electrical properties. Argonne
National Laboratory long has carried
out the major U.S. effort to synthesize
and identify organic superconductors.
Nearly 100 new superconductors of
this type have been produced, with
critical temperatures (at which a
superconductor loses all electrical
resistance) as high as -260 degrees
C, or -434 degrees F. Recently, the
first superconductor composed entirely
of organic components (with no metal
atoms) was synthesized, with a transition
temperature in this range. Although
this remains far lower than the highest
known transition temperature for ceramics,
scientists still expect that a high-temperature
organic superconductor may be possible,
such that liquid nitrogen (at -196
degrees C, or -321 degrees F) could
be used as the coolant instead of
the more costly liquid helium, thus
making practical applications more
feasible. The new compound has a two-dimensional,
layered structure, which may provide
significant insight into the nature
of superconductivity.
Scientific Impact:
These advances will help scientists
develop a theory of how organic superconductors
work and contribute to the design
of new materials with higher transition
temperatures. The all-organic material
is ideal for studies of magnetic and
charge transport properties because
there is no possibility of contamination
from metallic impurities.
Social Impact: Superconductivity
already has important applications,
such as medical diagnostic equipment,
and many more uses are possible if
transition temperatures are high enough.
The availability of purely organic
superconductors greatly expands the
possibilities, especially for applications
in which weight is a factor.
Reference: Ambient-Pressure
Superconductivity at 2.7 K and Higher
Temperatures in Derivatives of beta(ET)2IBr2:
Synthesis, Structure, and Detection
of Superconductivity. Williams, J.
M.; Wang, H. H.; Beno, M. A.; Emge,
T. J.; Sowa, L. M.; Copps, P. T.;
Behroozi, F.; Hall, L. N.; Carlson,
K. D.; Crabtree, G. W. Inorg.
Chem. 1984, 23, 3839-3841.
A New Ambient-Pressure Organic Superconductor,
kappa (ET)2Cu[N(CN)2Br,
with the Highest Transition Temperature
Yet Observed ( Inductive Onset Tc=11.6
K, Resistive Onset=12.5 K) Kini, A.
M.; Geiser, U.; Wang, H. H.; Carlson,
K. D.; Williams, J. M.; Kwok, W. K.;
Vandervoort, K. G.; Thompson, J. E.;
Stupka, D. L.; Jung, D.; Whangbo,
M.-H. Inorg. Chem. 1990,
29, 2555-2557.
From Semiconductor-Semiconductor Transition
(42 K) to the Highest-Tc
Organic Superconductor, kappa (ET)2Cu[N(CN)2Cl
(Tc=12.5 K) Williams, J.
M.; Kini, A. M.; Wang, H. H.; Carlson,
K. D.; Geiser, U.; Montgomery, L.
K.; Pyrka, G. J.; Watkins, D. M.;
Kommers, J. M.; Boryschuk, S. J.;
Strieby Crouch, A. V.; Kwok, W. K.;
Schirber, J. E.; Overmyer, D. L.;
Jung, D.; Whangbo, M.-H. Inorg.
Chem. 1990, 29, 3272-3274.
The First Organic Cation-radical Salt
Superconductor (Tc=4 K)
with an Organometallic Anion: Superconductivity,
Synthesis and Structure of kappa (ET)2M(CF3)4(C2H3X3).
Schlueter, J. A.; Geiser, U.; Williams,
J. M.; Wang, H. H.; Kwok, W. K.;Fendrich,
J. A.; Carlson, K. D.; Achenbach,
C. A.; Dudek, J. D.; Naumann, D.;
Roy, T.; Schirber, J. E.; Bayless,
W. R. J. Chem. Soc., Chem. Commun.
1994, 1599-1600.
Superconductivity at 5.2 K in an Electron
Donor Radical Salt of Bis (ethylenedithio)
tetrathiafulvalene (BEDT-TTF) with
the Novel Polyfluorinated Organic
Anion beta (ET)2SF5CH2CF2SO3)
Geiser, U.; Schlueter, J. A.; Wang,
H. H.; Kini, A. M.; Williams, J. M.;
Sche, P. P.; Zakowicz, H. I.; VanZile,
M. L.; Dudek, J. D.; Nixon, P. G.;
Winter, R.W.; Gard, G. L.; Ren, J.;
Whangbo, M.-H. J. Am. Chem. Soc.
1996, 118, 9996-9997.
URL:
http://www.msd.anl.gov/groups/occ/decades.htm
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 |