Superconductivity in Epitaxial Thin Films of Co-Doped SrFe2As2 with Bilayered FeAs Structures and their Magnetic Anisotropy

TL;DR

This paper reports the successful growth of superconducting epitaxial Co-doped SrFe2As2 thin films on single-crystal substrates, demonstrating their magnetic anisotropy and establishing a new platform for FeAs-based superconductor research.

Contribution

First demonstration of superconducting thin films of FeAs-based superconductors with detailed magnetic anisotropy analysis.

Findings

Superconducting transition at ~20 K in epitaxial films.

Zero-resistance maintained under 9 T magnetic field at 9 K for H parallel to c-axis.

Superconductivity observed up to 10 K for H parallel to a-axis.

Abstract

Superconducting epitaxial films of Fe-based layered arsenide, Co-doped SrFe2As2, were grown at 700oC on mixed perovskite (La, Sr)(Al, Ta)O3 (001) single-crystal substrates by pulsed-laser deposition. Both the epitaxial film and an (001)-oriented film grown at 600oC exhibited superconducting transitions at ~ 20 K. The zero-resistance states of the epitaxial film were sustained under a magnetic field (H) of 9 T at 9 K when H was parallel to the c-axis, while they were sustained at higher temperatures up to 10 K for H parallel to the a-axis. This is the first demonstration of superconducting thin films of FeAs-based new superconductors.