A new approach for improving global critical current density in Fe(Se0.5Te0.5) polycrystalline materials

Abstract

A novel method to prepare bulk Fe(Se0.5Te0.5) samples is presented, based on a melting process and a subsequent annealing treatment. With respect to the standard sintering technique, it produces much more homogeneous and denser samples, characterized by large and well interconnected grains. The resulting samples exhibit optimal critical temperature values, sharp resistive and magnetic transitions, large magnetic hysteresis loops and high upper critical fields are observed. Interestingly, the global critical current density is much enhanced as compared to the values reported in literature for bulk samples of the same 11 family, reaching about 103 A/cm2 at zero field at 4.2 K as assessed by magnetic, transport and magneto-optical techniques. Even more importantly, its field dependence turns out to be very weak, such that at μ_{0}H = 7 T it is suppressed only by a factor \sim2.

21 pages, 15 figures

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Cited by in corpus (13)

• Recent advances in iron-based superconductors toward applications
• The phase diagrams of iron-based superconductors: theory and experiments
• Strongly enhanced current densities in Sr0.6K0.4Fe2As2 superconducting tapes
• Effects of high energy proton irradiation on the superconducting properties of Fe(Se,Te) thin films
• Synthesis of CaKFe${}_4$As${}_4$ bulk samples with high critical current density using a spark plasma sintering technique
• Large transport Jc in Cu-sheathed Sr0.6K0.4Fe2As2 superconducting tape conductors
• Large transport critical currents and magneto-optical imaging of textured Sr1-xKxFe2As2 superconducting tapes
• The influence of the in-plane lattice constant on the superconducting transition temperature of FeSe0.7Te0.3 thin films
• Pinning properties of FeSeTe thin film through multifrequency measurements of the surface impedance
• Magnetic glassy phase in FeSeTe single crystals
• Pinning, flux flow resistivity and anisotropy of Fe(Se,Te) thin films from microwave measurements through a bitonal dielectric resonator
• Effect of impurity phase and high-pressure synthesis on the superconducting properties of CaKFe4As4
• Observation of Uniform Supercurrent Flow in Polycrystalline K-doped Ba122 by Combined Magneto-optical Imaging and Finite-element Modeling