Intergrain current flow in a randomly oriented polycrystalline SmFeAsO0.85 oxypnictide
arXiv:0907.4454 · doi:10.1063/1.3224198
Abstract
We report a direct current transport study of the local intergrain connections in a polycrystalline SmFeAsO0.85 (Sm1111) bulk, for which we earlier estimated significant intergranular critical current density Jc. Our combined low temperature laser scanning microscopy (LTLSM) and scanning electron microscopy observations revealed only few grain-to-grain transport current paths, most of which switched off when a magnetic field was applied. These regions typically occur where current crosses Fe-As, which is a normal-metal wetting-phase that surrounds Sm1111 grains, producing a dense array of superconducting-normal-superconducting contacts. Our study points out the need to reduce the amount of grain boundary-wetting Fe-As phase, as well as the crack density within pnictide grains, as these defects produce a multiply connected current-blocking network.
Submitted to Applied Physics Letters
References in corpus (12)
- Superconductivity at 43 K in Samarium-arsenide Oxides
- Superconductivity at 41 K and its competition with spin-density-wave instability in layered CeOFFeAs
- Very High Field Two-Band Superconductivity in LaFeAsO_0.89F_0.11
- Electron Correlations in the Low Carrier Density LaFeAsO0.89F0.11 Superconductor (Tc = 28 K)
- Superconductivity at 53.5 K in GdFeAsO1-delta
- Upper critical fields well above 100 T for the superconductor SmFeAsOF with T = 46 K
- Evidence for two distinct scales of current flow in polycrystalline Sm and Nd iron oxypnictides
- Superconducting properties of SmO1-xFxFeAs wires with Tc = 52 K prepared by the powder-in-tube method
- Intrinsic magnetic properties of NdFeAsOF superconductor from local and global measurements
- Evidence for electromagnetic granularity in the polycrystalline iron-based superconductor LaO0.89F0.11FeAs
- Combined microstructural and magneto optical study of current flow in polycrystalline forms of Nd and Sm Fe-oxypnictides
- Neutron Irradiation of Sm-1111
Cited by in corpus (28)
- Recent advances in iron-based superconductors toward applications
- New Fe-based superconductors: properties relevant for applications
- High intergrain critical current density in fine-grain (Ba0.6K0.4)Fe2As2 wires and bulks
- Template engineering of Co-doped BaFe2As2 single-crystal thin films
- Progress in wire fabrication of iron-based superconductors
- Weak-link behavior of grain boundaries in superconducting Ba(Fe1-xCox)2As2 bicrystals
- The behavior of grain boundaries in the Fe-based superconductors
- Realization of practical level current densities in Sr0.6K0.4Fe2As2 tape conductors for high-field applications
- Large transport critical currents of powder-in-tube Sr0.6K0.4Fe2As2/Ag superconducting wires and tapes
- A new approach for improving global critical current density in Fe(Se0.5Te0.5) polycrystalline materials
- Development of Powder-in-Tube Processed Iron Pnictide Wires and Tapes
- Grain boundary characteristics of Fe-based superconductors
- Low-temperature synthesis of SmFeAsO0.7F0.3 wires with high transport critical current density
- Evidence for electromagnetic granularity in polycrystalline Sm1111 iron-pnictides with enhanced phase purity
- Fabrication and transport properties of Sr0.6K0.4Fe2As2 multifilamentary superconducting wires
- Role of heat and mechanical treatments in the fabrication of superconducting Ba0.6K0.4Fe2As2 ex-situ Powder-In-Tube tapes
- Vortex pinning and dynamics in high performance Sr0.6K0.4Fe2As2 superconductor
- Disorder effects and current percolation in FeAs based superconductors
- Strengthened proximity effect at grain boundaries to enhance inter-grain supercurrent in Ba1-xKxFe2As2 superconductors
- Enhancement of transport critical current density of SmFeAsO1-xFx tapes fabricated by an ex-situ powder-in-tube method with a Sn-presintering process
- Density effect on critical current density and flux pinning properties of polycrystalline SmFeAsO1-xFx superconductor
- Effect of starting materials on the superconducting properties of SmFeAsO1-xFx tapes
- Anomalous Tail Effect on Resistivity Transition and Weak-link Behavior of Iron Based Superconductor
- Upper critical field, critical current density and thermally activated flux flow in CaFFe0.9Co0.1As superconductor
- α-FeAs-free SmFeAsO1-xFx by low temperature sintering with slow cooling
- Effect of the indium addition on the superconducting property and the impurity phase in polycrystalline SmFeAsO1-xFx
- Calculation of the transport critical current density of c-axis textured 122 iron-based superconductors
- Single crystal growth of BaFeCoAs without fluxing agent