Vortex pinning: A probe for nanoscale disorder in iron-based superconductors

• Published in: Physica. B, Condensed matter Vol. 407; no. 11; pp. 1746 - 1749
• Main Authors: van der Beek, C.J., Demirdis, S., Konczykowski, M., Fasano, Y., Cejas Bolecek, N.R., Pastoriza, H., Colson, D., Rullier-Albenque, F.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Kidlington Elsevier B.V 01.06.2012; Elsevier
• Subjects: Condensed matter; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Critical current; Disorders; Exact sciences and technology; Fluid flow; Flux pinning; Heterogeneity; Iron based superconductors; Nanostructure; Physics; Pinning; Properties of type I and type II superconductors; Superconductivity; Superconductors; Vortex lattices ,flux pinning, flux creep; Vortex pinning; Vortices; Heterogeneity; Iron based superconductors; Critical current; Vortex pinning; Critical current density; Flux line; Superconductivity; Magnetic field effects; Iron based superconductor; Nanometer scale; Quasiparticles; Superconductors; Flux pinning; Vortices; Inhomogeneity; Iron based arsenide
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2012.01.021

The pinning of quantized flux lines, or vortices, in the mixed state is used to quantify the effect of impurities in iron-based superconductors (IBS). Disorder at two length scales is relevant in these materials. Strong flux pinning resulting from nm-scale heterogeneity of the superconducting properties leads to the very disordered vortex ensembles observed in the IBS, and to the pronounced maximum in the critical current density jc at low magnetic fields. Disorder at the atomic scale, most likely induced by the dopant atoms, leads to “weak collective pinning” and a magnetic field-independent contribution jccoll. The latter allows one to estimate quasiparticle scattering rates.