Epitaxial growth and anisotropy of La(O,F)FeAs thin films deposited by Pulsed Laser Deposition

TL;DR

This paper reports the successful epitaxial growth of La(O,F)FeAs thin films using pulsed laser deposition, revealing their anisotropic superconducting properties and potential for electronic applications.

Contribution

It introduces a method for depositing high-quality La(O,F)FeAs thin films with controlled fluorine doping and characterizes their superconducting anisotropy.

Findings

Films exhibit nearly phase purity and strong c-axis texture.

Superconductivity onset at 11 K observed.

Anisotropic upper critical fields measured.

Abstract

LaFeAsO1-xFx thin films were deposited successfully on (001)-oriented LaAlO3 and MgO substrates from stoichiometric LaFeAsO1-xFx polycrystalline targets with fluorine concentrations up to x = 0.25 by PLD. Room temperature deposition and post annealing of the films yield nearly phase pure films with a pronounced c-axis texture and a strong biaxial in-plane orientation. Transport measurements show metallic resistance and onset of superconductivity at 11 K. Hc2(T) was determined by resistive measurements and yield Hc2 values of 3 T at 3.6 K for B||c and 6 T at 6.4 K for B||ab.