Investigation of pressure impact on physical characteristics of FeSe chalcogenide superconductor: Insights from first principles calculation

Abstract

Understanding the high-pressure physical characteristics of iron selenium (FeSe) superconductors is crucial to comprehending their superconducting abilities. First-principles Density Functional Theory has been computed in the present calculations to analyze the pressure impact on structural, mechanical, electronic and superconducting characteristics along with the Debye and melting temperatures of tetragonal FeSe. The analysis of mechanical characteristics suggests that this compound remains mechanically stable up to a pressure of 20 GPa. The applied hydrostatic pressure is observed to have a significant impact on the elastic moduli and the anisotropic behaviour of FeSe at all pressure conditions. Similarly, the first indication of ductility is observed approximately at 8 GPa and then it increases as pressure rises. At 0 GPa, the optimized structural values are seen to line up with the available data. The variation of structural parameters and electronic factors of FeSe with applied pressure is also mentioned here. Moreover, the assessment of the compound’s electronic characteristics provides strong evidence for its metallic nature and the rise in a number of states at the Fermi energy level with applied pressure may be the cause for the increase in the superconducting critical temperature of FeSe with pressure.