Recent Developments in Fe-Based Superconductors Towards Understanding Their Vortex Matter and Possible Applications

In recent years, the field of Fe-based superconductors (FBS) has consolidated to a steady progress in sample qualities, fundamental understanding of their unconventional superconductivity, as well as in optimizing their properties with regard to possible applications.<br/>The high-field application-relevant FBS usually show relatively high critical temperatures and critical fields in combination with low electronic anisotropies. Furthermore, grain boundaries in these materials show larger transparencies than those in cuprates, which eases the production of wires and tapes. Several projects worldwide aim to fabricate high-quality and/or long-length wires and tapes, may it be via powder-in-tube or coated-conductor technology. However, the class of Fe-based superconductors is very rich in crystal structures (despite the common feature of FeAs or FeSe layers), hence dimensionality and anisotropy, kind of doping (electron, hole, isovalent, undoped, direct/indirect etc.), and chemical composition and stoichiometry. Comparing these different phases in their (micro)structural and magneto-electrical properties can help elucidate the specifics of these compounds with regard to nature of superconductivity and their vortex matter, as well as help optimizing the transport properties of application-relevant FBS.<br/>This talk will give an overview over recent developments in growth, measurements, and optimization of Fe-based superconductors with focus on thin films, vortex matter, and pinning enhancement.