Evidence of Inhomogeneous Superconductivity in FeTe$_{1-x}$Se$_x$ Thin Film Using Scotch-Tape Method

TL;DR

This study demonstrates inhomogeneous superconductivity in FeTe$_{1-x}$Se$_x$ thin films fabricated via Scotch-tape method, highlighting the impact of excess Fe concentration on superconducting properties.

Contribution

It provides direct evidence of inhomogeneous superconductivity in FeTe$_{1-x}$Se$_x$ thin films and links it to Fe excess inhomogeneity.

Findings

Superconductivity varies among films from the same bulk sample.

Lower excess Fe correlates with better superconductivity and sharper transition.

Inhomogeneity due to Fe excess affects superconducting behavior.

Abstract

We have fabricated thin films of FeTe$_{1-x}$Se$_x$ using a scotch-tape method. The superconductivities of the thin films are different from each other although these films were fabricated from the same bulk sample. The result clearly presents the inhomogeneous superconductivity in FeTe$_{1-x}$Se$_x$. The difference comes from inhomogeneity due to the excess Fe concentration. The resistivity of a thin film with low excess Fe shows good superconductivity with the sharp superconducting-transition width and more isotropic superconductivity.