Nematic properties of FeSe$_{1-x}$Te$_{x}$ crystals with a low Te content

TL;DR

This study investigates the nematic properties and electronic transport behavior of FeSe$_{1-x}$Te$_x$ crystals with low tellurium content, revealing carrier inversion and nematic transition signatures through resistivity and Hall measurements.

Contribution

It provides new insights into the nematic transitions and carrier type inversion in low-Te FeSe$_{1-x}$Te$_x$ crystals, expanding understanding of their electronic phase behavior.

Findings

Weak anomalies indicating nematic transitions at elevated temperatures.

Carrier type inversion from holes to electrons at x > 0.17.

Elastoresistance sign change correlating with doping type.

Abstract

We report on the synthesis and physical properties of FeSe$_{1-x}$Te$_x$ single crystals with a low Te content (x = 0.17, 0.21, 0.25), where the replacement of Se with Te partially suppresses superconductivity. Resistivity and Hall effect measurements indicate weak anomalies at elevated temperatures ascribed to nematic transitions. A quasi-classical analysis of transport data, including in a pulsed magnetic field of up to 25 T, confirms the inversion of majority carriers type from holes in FeSe to electrons in FeSe$_{1-x}$Te$_x$ at x $>$ 0.17. The temperature-dependent term in the elastoresistance of the studied compositions has a negative sign, which means that for substituted FeSe compositions, the elastoresistance is positive for hole-doped materials and negative for electron-doped materials just like in semiconductors such as silicon and germanium.