Superconductivity in CuIr2-xAlxTe4 telluride chalcogenides

TL;DR

This study investigates how Al doping affects the charge-density-wave and superconductivity in CuIr2-xAlxTe4 telluride chalcogenides, revealing suppression of CDW and enhancement of superconductivity with a maximum Tc of 2.75 K.

Contribution

It provides the first systematic analysis of the interplay between CDW and superconductivity in CuIr2-xAlxTe4, including a phase diagram and evidence of bulk superconductivity.

Findings

Al doping destroys CDW order

Superconducting Tc reaches 2.75 K at x=0.075

Normalized specific heat jump exceeds BCS value

Abstract

The relationship between charge-density-wave (CDW) and superconductivity (SC), two vital physical phases in condensed matter physics, has always been the focus of scientists' research over the past decades. Motivated by this research hotspot, we systematically studied the physical properties of the layered telluride chalcogenide superconductors CuIr2-xAlxTe4. Through the resistance and magnetization measurements, we found that the CDW order was destroyed by a small amount of Al doping. Meanwhile, the superconducting transition temperature (Tc) kept changing with the change of doping amount and rose towards the maximum value of 2.75 K when x = 0.075. The value of normalized specific heat jump for the highest Tc sample CuIr1.925Al0.075Te4 was 1.53, which was larger than the BCS value of 1.43 and showed that bulk superconducting nature. In order to clearly show the relationship between SC and CDW states, we propose a phase diagram of Tc vs. doping content.