Anomalous Charge Density Wave State Evolution and Dome-like Superconductivity in CuIr2Te4-xSex Chalcogenides

TL;DR

This study explores how substituting Se for Te in CuIr2Te4 affects charge density wave behavior and induces a dome-shaped superconducting phase, revealing complex interplay between doping, structure, and electronic states.

Contribution

It demonstrates the anomalous evolution of CDW and superconductivity in CuIr2Te4-xSex, highlighting the disorder-induced nature of CDW transitions and the dome-like Tc variation.

Findings

Superconducting Tc peaks at 2.83 K for x=0.1

CDW-like transition is suppressed then re-emerges with doping

Structural stability confirmed across temperature range

Abstract

We report the anomalous charge density wave (CDW) state evolution and dome-like superconductivity (SC) in CuIr2Te4-xSex series. Room temperature powder X ray-diffraction (PXRD) results indicate that CuIr2Te4-xSex compounds retain the same structure as the host CuIr2Te4 and the unit cell constants a and c manifest a linear decline with increasing Se content. Magnetization, resistivity and heat capacity results suggest that superconducting transition temperature (Tc) exhibits a weak dome-like variation as substituting Te by Se with the maximum Tc = 2.83 K for x = 0.1 followed by suppression in Tc and simultaneous decrease of the superconducting volume fraction. Unexpectedly, the CDW-like transition (TCDW) is suppressed with lower Se doping but re-emerges at higher doping. Meanwhile, the temperature-dependent XRD measurements show that the trigonal structure is stable at 20 K, 100 K and 300 K for the host sample and the doping composition with x = 0.5, thus we propose that the behaviour CDW-like transition arises from the disorder effect created by chemical doping and is not related to structural transition. The lower and the upper critical fields of these compounds are also addressed.