Potassium-doped BaFe2As2 superconducting thin films with a transition temperature of 40 K

TL;DR

This paper reports the successful growth of potassium-doped BaFe2As2 superconducting thin films with transition temperatures around 40 K, demonstrating good superconducting properties and high upper critical fields.

Contribution

It introduces a method for fabricating potassium-doped BaFe2As2 thin films with high Tc using pulsed laser deposition on different substrates.

Findings

Transition temperatures of 40 K and 39 K on different substrates.

Good bulk superconducting properties below 36 K and 30 K.

Estimated upper critical field of about 155 T.

Abstract

We report the growth of potassium-doped BaFe2As2 thin films, where the major charge carriers are holes, on Al2O3 (0001) and LaAlO3 (001) substrates by using an ex-situ pulsed laser deposition technique. The measured Tc's are 40 and 39 K for the films grown on Al2O3 and LaAlO3, respectively and diamagnetism indicates that the films have good bulk superconducting properties below 36 and 30 K, respectively. The X-ray diffraction patterns for both films indicated a preferred c-axis orientation, regardless of the substrate structures of LaAlO3 and Al2O3. The upper critical field at zero temperature was estimated to be about 155 T.