Thermoelectric studies of Ir$_{1-x}$Rh$_{x}$Te$_{2}$ (0 $\leqslant x \leqslant $ 0.3)

TL;DR

This study investigates how Rh substitution in IrTe$_2$ affects its thermoelectric properties and induces low-temperature superconductivity, highlighting differences from Se substitution effects.

Contribution

It provides new insights into the impact of isovalent Rh substitution on the structural, electronic, and superconducting properties of IrTe$_2$.

Findings

Superconductivity emerges at low temperatures with Rh substitution.

Structural transition is suppressed as Rh content increases.

Superconductivity likely driven by electron-phonon coupling.

Abstract

We report thermoelectric properties of Ir$_{1-x}$Rh$_x$Te$_2$ ($0 \leqslant x \leqslant 0.3$) alloy series where superconductivity at low temperatures emerges as the high-temperature structural transition ($T_s$) is suppressed. The isovalent ionic substitution of Rh into Ir has different effects on physical properties when compared to the anionic substitution of Se into Te, in which the structural transition is more stable with Se substitution. Rh substitution results in a slight reduction of lattice parameters and in an increase of number of carriers per unit cell. Weak-coupled BCS superconductivity in Ir$_{0.8}$Rh$_{0.2}$Te$_2$ that emerges at low temperature ($T_c^{zero}$ = 2.45 K) is most likely driven by electron-phonon coupling rather than dimer fluctuations mediated pairing.