US-Tech Online. -> July 08 Issue- New Iron-Based Superconductors

July 08 Issue- New Iron-Based Superconductors

The magnetic structure of the new iron-based superconductors was determined at the thermal triple-axis spectrometer at the NIST Center for Neutron Research. Physicists Jeff Lynn and Ying Chen prepare the instrument for use. Photo Copyright: Robert Rathe.

Gaithersburg, MD — Researchers working at the National Institute of Standards and Technology (NIST) have discovered that a new class of iron-based superconductors discovered earlier this year shares similar unusual magnetic properties with previously known high-temperature superconductors based on copper-oxide materials. The work emphasizes a critical but as yet unexplained link between magnetism and high-temperature superconductors.

The announcement on the Web site of the journal Nature (Nature Advanced Online Publication, May 28, 2008) was made by C. de la Cruz, Q. Huang, J.W. Lynn, J. Li, W. Ratcliff II, J.L. Zarestky, H.A. Mook, G.F. Chen, J.L. Luo, N.L. Wang and P. Dai; "Magnetic order close to superconductivity in the iron-based layered La(O1-xFx)FeAs systems."

The importance of magnetism to high-temperature (HTc) superconductors is remarkable because magnetism strongly interferes with conventional, low-temperature superconductors, but now may prove to be an integral element of HTc materials. These superconductors may one day enable energy and environmental gains by significantly improving the efficiency of electricity storage and transmission over long distances.

The team working at NIST, which included researchers from the University of Tennessee at Knoxville, Oak Ridge National Laboratory, the University of Maryland, Ames Laboratory, Iowa State University and the Beijing National Laboratory for Condensed Matter Physics, used neutron beams to demonstrate that, like copper-oxide superconductors, the new iron-based HTc materials discovered earlier this year by Japanese researchers share an unusual magnetic structure with magnetically active layers interspersed with layers of nonmagnetic material.

For more details, see: "New Iron-based and Copper-Oxide High Temperature Superconductors Share Key Magnetic Properties" at http://www.nature.com/nature/journal/v453/n7197/full/nature07057.html

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