Atomic, electronic, and superconducting properties of Zr$_2$Ir compound

TL;DR

This study comprehensively analyzes the structural, electronic, mechanical, phononic, and superconducting properties of Zr$_2$Ir, revealing its stability, metallic nature, and superconducting transition temperature around 7.5 K, with SOC effects slightly reducing its critical temperature.

Contribution

First-principles calculations of Zr$_2$Ir's properties, including stability, mechanical behavior, electronic structure, and superconductivity, highlighting the impact of spin-orbit coupling.

Findings

Zr$_2$Ir is mechanically and dynamically stable.

It exhibits metallic character with a superconducting transition temperature around 7.5 K.

SOC slightly decreases the critical temperature and electron-phonon coupling constant.

Abstract

We have investigated the structural, electronic, mechanical, phononic, and superconducting properties of the Zr$_2$Ir compound with a body-centered tetragonal crystal structure using first-principles calculations. Our analysis reveals that the Zr$_2$Ir compound shows mechanical and dynamically stable by using with and without spin-orbit coupling (SOC) effect. After calculating some properties such as elastic constants, Bulk modulus, Young's modulus, Poisson ratio, Debye temperature, and sound velocity, we found that Zr$_2$Ir is ductile. When the elastic constants $C_{11}$ and $C_{33}$ are compared, it is determined that the situation changes in the opposite direction under the effect of SOC, that is, more compressibility along the x-axis turns into the z-axis. Here, the electronic band structure and intensity of the states calculated for the compound show a metallic character. The superconducting critical temperature ($T_c$) and electron-phonon coupling constant ($\lambda$) were found to be 7.50 K and 0.93 without SOC and 7.62 K and 0.96 with SOC, respectively. We determined that although the Zr$_2$Ir compound has a strong electron-phonon coupling regime, the inclusion of SOC slightly reduces its critical temperature and electron-phonon coupling constant.