In-situ growth of superconducting NdFeAs(O,F) thin films by Molecular Beam Epitaxy

TL;DR

This paper reports the successful in-situ growth of high-quality NdFeAs(O,F) superconducting thin films on GaAs substrates using Molecular Beam Epitaxy, achieving transition temperatures up to 48 K without ex-situ heat treatment.

Contribution

It demonstrates the first in-situ growth of NdFeAs(O,F) thin films with high Tc, advancing fabrication techniques for Fe-based superconductor devices.

Findings

Achieved in-situ growth of NdFeAs(O,F) films on GaAs.

Superconducting transition temperature up to 48 K.

No ex-situ heat treatment required.

Abstract

The recently discovered high temperature superconductor F-doped LaFeAsO and related compounds represent a new class of superconductors with the highest transition temperature (Tc) apart from the cuprates. The studies ongoing worldwide are revealing that these Fe-based superconductors are forming a unique class of materials that are interesting from the viewpoint of applications. To exploit the high potential of the Fe-based superconductors for device applications, it is indispensable to establish a process that enables the growth of high quality thin films. Efforts of thin film preparation started soon after the discovery of Fe-based superconductors, but none of the earlier attempts had succeeded in an in-situ growth of a superconducting film of LnFeAs(O,F) (Ln=lanthanide), which exhibits the highest Tc to date among the Fe-based superconductors. Here, we report on the successful growth of NdFeAs(O,F) thin films on GaAs substrates, which showed well-defined superconducting transitions up to 48 K without the need of an ex-situ heat treatment.