Investigation of Transport Properties for FeSe$_{1-x}$Te$_x$ Thin Films under Magnetic Fields

TL;DR

This study explores how magnetic fields affect the electrical transport properties of FeSe$_{1-x}$Te$_x$ thin films, revealing significant differences in superconductivity and electronic structure across different compositions.

Contribution

It provides new insights into the composition-dependent transport and superconducting properties of FeSe$_{1-x}$Te$_x$ thin films under magnetic fields.

Findings

Superconducting transition width increases with magnetic field for x=0.2-0.4.

Hall coefficient behavior changes drastically between x=0.1 and 0.2.

Distinct electronic structures are observed between low and higher Te content.

Abstract

We investigated the transport properties under magnetic fields of up to 9 T for FeSe$_{1-x}$Te$_x$ thin films on CaF$_2$. Measurements of the temperature dependence of the electrical resistivity revealed that for $x = 0.2 - 0.4$, where $T_{\rm c}$ is the highest, the width of the superconducting transition increased with increasing magnetic field, while the width was almost the same with increasing magnetic field for $x = 0 - 0.1$. In addition, the temperature dependence of the Hall coefficient drastically changed between $x = 0.1$ and $0.2$ at low temperatures. These results indicate that clear differences in the nature of the superconductivity and electronic structure exist between $x=0-0.1$ and $x \ge 0.2$.