"Magnetic order close to superconductivity in the iron-based
layered La0(1-x)F(x)FeAs systems," by Clarina de la Cruz and 10
others, Nature, 7197(453): 899-902, 12 June 2008.
[Authors' affiliations: University of Tennessee, Knoxville; Oak Ridge
National Lab, TN; NIST, Gaithersburg, MD; University of Maryland, College
Park; Ames Lab and Iowa State University; Beijing National Laboratory for
Condesed Matter Physics, China]
Abstract: "Following the discovery of long-range
antiferromagnetic order in the parent compounds of
high-transition-temperature (high-Tc) copper oxides, there have been
efforts to understand the role of magnetism in the superconductivity that
occurs when mobile 'electrons' or 'holes' are doped into the
antiferromagnetic parent compounds. Superconductivity in the newly
discovered rare-earth iron-based oxide systems ROFeAs (R, rare-earth metal)
also arises from either electron or hole doping of their
non-superconducting parent compounds. The parent material LaOFeAs is
metallic but shows anomalies near 150 K in both resistivity and
d.c. magnetic susceptibility. Although optical conductivity and theoretical
calculations suggest that LaOFeAs exhibits a spin-density-wave (SDW)
instability that is suppressed by doping with electrons to induce
superconductivity, there has been no direct evidence of SDW order. Here we
report neutron- scattering
experiments that demonstrate that LaOFeAs undergoes an abrupt structural
distortion below 155 K, changing the symmetry from tetragonal (space group
P4/nmm) to monoclinic (space group P112/n) at low
temperatures, and then, at ~137 K, develops long-range SDW-type
antiferromagnetic order with a small moment but simple magnetic structure.
Doping the system with fluorine suppresses both the magnetic order and the
structural distortion in favour of superconductivity. Therefore, like
high-Tc copper oxides, the superconducting regime in these iron-based
materials occurs in close proximity to a long-range-ordered
antiferromagnetic ground
state."
This 2008 report from Nature was cited 34
times in current journal articles indexed by Clarivate
during September-October 2008. Of all non-review papers published in the
last two years and designated as "chemistry" by the Hot Papers Database
(although a good many citations to this interdisciplinary report derive
from physics journals), only one paper collected a higher number of
citations during that two-month period. In fact, this is one of a trio of
reports on iron-based superconductors currently occupying the top three
spots in chemistry's 10 most cited. Prior to the most recent
bimonthly count, citations to the paper have accrued as follows:
July-August 2008: 15 citations
Current citations to date: 49
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