Artificially engineered superlattices of pnictide superconductor

TL;DR

This paper reports the fabrication of pnictide superlattices with enhanced superconducting properties, demonstrating large critical current densities and irreversibility fields, and exploring their potential for advanced superconducting devices.

Contribution

It introduces the creation of undoped Ba-122 / Co-doped Ba-122 superlattices with nanoparticle arrays and sharp interface SrTiO3 / Co-doped Ba-122 superlattices, advancing superlattice engineering in pnictides.

Findings

Large Jc and Hirr enhancements over wide angular ranges.

Formation of ab-aligned nanoparticle arrays along defects.

Successful fabrication of structurally modulated superlattices with sharp interfaces.

Abstract

Significant progress has been achieved in fabricating high quality bulk and thinfilm iron-based superconductors. In particular, artificial layered pnictide superlattices offer the possibility of tailoring the superconducting properties and understanding the mechanism of the superconductivity itself. For high field applications, large critical current densities (Jc) and irreversibility fields (Hirr) are indispensable along all crystal directions. On the other hand, the development of superconducting devices such as tunnel junctions requires multilayered heterostructures. Here we show that artificially engineered undoped Ba-122 / Co doped Ba-122 compositionally modulated superlattices produce ab-aligned nanoparticle arrays. These layer and self-assemble along c-axis aligned defects, and combine to produce very large Jc and Hirr enhancements over a wide angular range. We also demonstrate a structurally modulated SrTiO3 (STO) / Co doped Ba-122 superlattice with sharp interfaces. Success in superlattice fabrication involving pnictides will aid the progress of heterostructured systems exhibiting novel interfacial phenomena and device applications.