Highly textured oxypnictide superconducting thin films on metal substrates

Abstract

Highly textured NdFeAs(O,F) thin films have been grown on ion beam assisted deposition (IBAD)-MgO/Y2O3/Hastelloy substrates by molecular beam epitaxy. The oxypnictide coated conductors showed a superconducting transition temperature (Tc) of 43 K with a self-field critical current density (Jc) of 7.0 x 104 A/cm2 at 5 K, more than 20 times higher than powder-in-tube processed SmFeAs(O,F) wires. Albeit higher Tc as well as better crystalline quality than Co-doped BaFe2As2 coated conductors, in-field Jc of NdFeAs(O,F) was lower than that of Co-doped BaFe2As2. These results suggest that grain boundaries in oxypnictides reduce Jc significantly compared to that in Co-doped BaFe2As2 and, hence biaxial texture is necessary for high Jc.

4 pages, 4 figures

References in corpus (5)

• Advantageous grain boundaries in iron pnictide superconductors
• High intergrain critical current density in fine-grain (Ba0.6K0.4)Fe2As2 wires and bulks
• Biaxially textured cobalt-doped BaFe2As2 films with high critical current density over 1 MA/cm2 on MgO-buffered metal-tape flexible substrates
• Epitaxial growth of FeSe${}_{0.5}$Te${}_{0.5}$ thin films on CaF${}_2$ substrates with high critical current density
• Versatile fluoride substrates for Fe-based superconducting thin films