New Fe-based superconductors: properties relevant for applications

Journal Article · Thu Jan 01 00:00:00 EST 2009 · Superconductor Science & Technology

OSTI ID:988737

Putti, M ^[1]; Pallecchi, I ^[1]; Bellingeri, E ^[1]; Cimberle, M R ^[1]; Tropeano, M ^[1]; Ferdeghini, C ^[1]; Palenzona, A ^[1]; Tarantini, C ^[2]; Yamamoto, A. ^[2]; Jiang, J ^[2]; Jaroszynski, J ^[2]; Kametani, F ^[2]; Abraimov, D ^[2]; Polyanskii, A. A. ^[2]; Weiss, J. D. ^[2]; Hellstrom, E. E. ^[2]; Gurevich, A. ^[2]; Larbalestier, D. C. ^[2]; Jin, Rongying ^[3]; Sales, Brian C ^[3] ; Safa-Sefat, Athena ^[3]; McGuire, Michael A ^[3]; Mandrus, David ^[3]; Cheng, P. ^[4]; Jia, Y. ^[4]; Wen, H. H. ^[4]; Lee, S ^[5]; Eom, C. B. ^[5]

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1. CNR-INFM-LAMIA & Universita di Genova, Italy
2. Florida State University
3. ORNL
4. Institute of Physics, Beijing, China
5. University of Wisconsin

Less than two years after the discovery of high temperature superconductivity in oxypnictide LaFeAs(O, F) several families of superconductors based on Fe layers (1111, 122, 11, 111) are available. They share several characteristics with cuprate superconductors that compromise easy applications, such as the layered structure, the small coherence length and unconventional pairing. On the other hand, the Fe-based superconductors have metallic parent compounds and their electronic anisotropy is generally smaller and does not strongly depend on the level of doping, and the supposed order parameter symmetry is s-wave, thus in principle not so detrimental to current transmission across grain boundaries. From the application point of view, the main efforts are still devoted to investigate the superconducting properties, to distinguish intrinsic from extrinsic behaviors and to compare the different families in order to identify which one is the fittest for the quest for better and more practical superconductors. The 1111 family shows the highest T{sub c}, huge but also the most anisotropic upper critical field and in-field, fan-shaped resistive transitions reminiscent of those of cuprates. On the other hand, the 122 family is much less anisotropic with sharper resistive transitions as in low temperature superconductors, but with about half the T{sub c} of the 1111 compounds. An overview of the main superconducting properties relevant to applications will be presented. Upper critical field, electronic anisotropy parameter, and intragranular and intergranular critical current density will be discussed and compared, where possible, across the Fe-based superconductor families.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 988737
• Journal Information: Superconductor Science & Technology, Vol. 23, Issue 3; ISSN 0953-2048
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
IRON COMPOUNDS
COHERENCE LENGTH
CRITICAL CURRENT
CRITICAL FIELD
ORDER PARAMETERS
SUPERCONDUCTIVITY
SUPERCONDUCTORS