Superconductivity of FeSe$_{1-x}$Te$_{x}$ Thin Films Grown by Pulsed Laser Deposition

TL;DR

This study successfully grew FeSe$_{1-x}$Te$_{x}$ thin films using pulsed laser deposition, demonstrating that substrate-induced strain significantly affects their superconducting transition temperatures.

Contribution

It presents a method for growing FeSe$_{1-x}$Te$_{x}$ thin films with controlled superconducting properties via pulsed laser deposition on different substrates.

Findings

Superconductivity observed at 6.7 K on MgO substrate.

On LaSrAlO$_{4}$, only onset at 2.6 K without zero resistivity.

Epitaxial strain strongly influences superconducting behavior.

Abstract

FeSe$_{1-x}$Te$_{x}$ thin films with PbO-type structure are successfully grown on MgO(100) and LaSrAlO$_{4}$(001) substrates from FeSe$_{1-x}$Te$_{x+d}$ polycrystalline targets by pulsed-laser deposition. The film deposited on the MgO substrate (film thickness $\sim$ 63 nm) shows superconductivity at 6.7 K (onset) and 5.5 K (zero resistivity). On the other hand, the film deposited on the LaSrAlO$_{4}$ substrate (film thickness $\sim$ 52 nm) exhibits only the onset of superconducting transition at 2.6 K, but does not show zero resistivity. This indicates the strong influence of epitaxial strain to superconducting properties of FeSe$_{1-x}$Te$_{x}$ thin films.