Vortex creep and critical current densities in superconducting (Ba,K)Fe2As2 single crystals
Journal Article
·
· Physical Review. B, Condensed Matter and Materials Physics
- Ecole Polytechnique, Palaiseau (France)
- Ames Laboratory (AMES), Ames, IA (United States)
- Chinese Academy of Sciences (CAS), Beijing (China)
- Nanjing University (China)
- Ames Laboratory, and Iowa State University, Ames, IA (United States)
We report the surprisingly rapid relaxation of the sustainable current density in the critical state of single-crystalline Ba1-xKxFe2As2 is investigated for magnetic fields oriented parallel to the c axis and to the ab plane, respectively. Due to the inadequacy of standard analysis procedures developed for flux creep in the high-temperature superconducting cuprates, we develop a simple, straightforward data treatment technique that reveals the creep mechanism and the creep exponent μ. At low magnetic fields, below the second magnetization peak, μ varies only slightly as a function of temperature and magnetic flux density B. Usin the data, we determine the temperature and field dependencies of the effective activation barrier for creep. At low temperatures, the measured current density approaches the zero-temperature critical current density (in the absence of creep) to within a factor 2, thus lending credence to earlier conclusions drawn with respect to the pinning mechanism. The comparable values of the experimental screening current density and the zero-temperature critical current density reveal the limited usefulness of the widely used “interpolation formula.”
- Research Organization:
- Ames Laboratory (AMES), Ames, IA (United States)
- Sponsoring Organization:
- Ecole Polytechnique; French National Research Agency; National Creative Research Initiative; USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE)
- Grant/Contract Number:
- AC02-07CH11358
- OSTI ID:
- 1052076
- Report Number(s):
- IS-J--7762
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 2 Vol. 86; ISSN 1098-0121
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Flux creep and critcal-current anisotropy in Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub 8+//sub delta/
High-field critical current densities in Bi sub 2 Sr sub 2 Ca sub 1 Cu sub 2 O sub 8+ x /Ag wires
Strong magnetic field dependence of critical current densities and vortex activation energies in an anisotropic clean MgB2 thin film
Journal Article
·
Fri Mar 31 23:00:00 EST 1989
· Phys. Rev. B: Condens. Matter; (United States)
·
OSTI ID:6335555
High-field critical current densities in Bi sub 2 Sr sub 2 Ca sub 1 Cu sub 2 O sub 8+ x /Ag wires
Journal Article
·
Sun Dec 03 23:00:00 EST 1989
· Applied Physics Letters; (USA)
·
OSTI ID:5118343
Strong magnetic field dependence of critical current densities and vortex activation energies in an anisotropic clean MgB2 thin film
Journal Article
·
Mon Nov 24 19:00:00 EST 2014
· Solid State Communications
·
OSTI ID:2560726