Intrinsic magnetic properties of the superconductor NdFeAsO0.9F0.1 from local and global measurements

TitleIntrinsic magnetic properties of the superconductor NdFeAsO0.9F0.1 from local and global measurements
Publication TypeJournal Article
Year of Publication2009
AuthorsProzorov R, Tillman ME, Mun ED, Canfield PC
Journal TitleNew Journal of Physics
Volume11
Pages035004
Date Published03/25
ISBN Number1367-2630
Accession NumberISI:000270976100001
Keywordsfield, high-temperature superconductors, state
Abstract

Magneto-optical imaging was used to study the local magnetization in polycrystalline NdFeAsO0.9F0.1 (NFAOF). Individual crystallites up to similar to 200 x 100 x 30 mu m(3) in size could be mapped at various temperatures. The in-grain, persistent current density is about j similar to 10(5) A cm(-2) and the magnetic relaxation rate in a remanent state peaks at about T-m similar to 38 K. By comparison with the total magnetization measured in a bar-shaped, dense, polycrystalline sample, we suggest that NdFeAsO0.9F0.1 is similar to high-T-c cuprates, in between Bi2Sr2CaCu2O8+x and YBa2Cu3O7-x in terms of the vortex response in the mixed state. We find an apparent crossover in the pinning strength at similar to 38 K that could be associated either with vortex decoupling or melting. Below this temperature the static and dynamic vortex behavior is consistent with the collective pinning and creep.

URL<Go to ISI>://000270976100001
DOI10.1088/1367-2630/11/3/035004