Peak effect and superconducting properties of SmFeAsO0.8F0.2wires

Ta-sheathed SmFeAsO 0.8 F 0.2 superconducting wires with T c = 52.5 K have been fabricated using the powder-in-tube (PIT) method and the superconducting properties of the wires have been investigated. The wires exhibit a very large intragrain critical current density at a temperature below 30 K. A peak effect with maximal J c = 0.6 MA cm −2 at 10 K under 6 T field was observed. The peak field H pear is strongly temperature-dependent. A severe weak-link effect depresses the development of global supercurrent owing to a very short coherence length. The wires also show a power law temperature dependence for the irreversibility line with . The H – T phase diagram was found to be similar to that of other superconducting cuprates.