Iron-based superconductors (IBS) are highly promising candidates for high-field magnet applications due to their ultrahigh upper critical fields and very small anisotropy. Recently, significant progress has been made in enhancing the critical current density (Jc) of IBS wires and tapes based on the powder-in-tube technique. For instance, a high transport Jc above 2×105 A/cm2(4.2 K, 10 T) has been achieved in IBS short tape samples, and the Jc of multi-filament 100-m long tapes was continuously improved, reaching 6×104 A/cm2 at 4.2 K, 10 T. These results demonstrate great potential of IBS wires and tapes for high-field applications. In this presentation, I will introduce our new findings on the formation and modulation mechanisms in melting-processed Ba-Fe-Co-As IBS, as well as the phase formation and reaction kinetics of Ba-K-Fe-As system. These insights provide valuable information for the impurity control and future Jc improvement for Ba-122 IBS. Then I will present some new strategies and methods developed for fabricating Cu/Ag and SS/Ag composite sheathed IBS tapes, in which the grain texture, grain boundaries and pinning landscape were well engineered to achieve new record-high Jc values. Finally, I will highlight some remarkable recent advances relevant to practical applications, including long-length wires, joints, pancake & racetrack coils, and cables. The prospects of IBS materials for future applications will also be discussed.
Keywords: iron-based superconductors, superconducting wires, critical current density, flux pinning