A comprehensive ab-initio insights into the pressure dependent mechanical, phonon, bonding, electronic, optical, and thermal properties of CsV3Sb5 Kagome compound

TL;DR

This study provides a detailed first-principles analysis of CsV3Sb5, revealing its structural, mechanical, electronic, optical, and thermal properties and their pressure dependence, highlighting its stability, ductility, and optical applications.

Contribution

First comprehensive DFT-based investigation of CsV3Sb5's diverse physical properties and their pressure-dependent behavior, including stability, bonding, and optical characteristics.

Findings

CsV3Sb5 is mechanically and dynamically stable at zero pressure.

The compound exhibits metallic electronic and optical properties.

Structural instability occurs around 18 GPa.

Abstract

In this paper, we have presented a comprehensive study of the physical properties of Kagome superconductor CsV3Sb5 using the density functional theory (DFT). The structural, mechanical, electronic, atomic bonding, hardness, thermodynamic, and optical properties, and their pressure dependences have been investigated for the first time. The calculated ground state lattice parameters and volume are in excellent agreement with available experimental results. The estimated single-crystal elastic constants ensured the mechanical stability of the compound, whereas phonon spectra endorse dynamical stability at zero pressure. The electronic band structure, energy density of states, optical properties confirmed the metallic features. The Pugh ratio, Poisson's ratio of the compound revealed softness and ductility. The hardness, estimated from several formulae, is quite low while the machinability index predicted good machinability with excellent dry lubricating properties. The compound shows tendency towards structural instability at a pressure around 18 GPa. The optical constants have also been studied to correlate those with electronic properties and to predict possible applications of this compound. Both mechanical and optical properties show anisotropy.CsV3Sb5 is predicted to be an efficient absorber of ultraviolet radiation. The compound is also an efficient reflector of visible light.