The Impact of Hydrostatic Pressure on the Structural, Mechanical, Thermal, and Optoelectronic Characteristics of the RbV3Sb5 Kagome Compound: Ab initio Approach.

Abstract

We studied the RbV₃Sb₅ kagome compound's structural, mechanical, thermal, and optoelectronic properties. Mulliken and Hirshfeld population analysis found ionic and covalent connections in RbV₃Sb₅. The Born stability criterion shows that pure RbV₃Sb₅ is mechanically stable. The precise measurement of 3.96 indicates that our sample has higher machinability at 20 GPa. Low anticipated hardness of RbV₃Sb₅ suggests it can be used as a soft solid lubricant. Hardness ratings rise with pressure, however there are exceptions. Pressure causes large nonmonotonic changes in RbV₃Sb₅'s anisotropic characteristics. A comparable 20 GPa Zener anisotropic value, RbV₃Sb₅ has the highest. The structure's projected Debye temperature at 0 GPa is 284.39 K, indicating softness. Dispersion curves with negative frequencies suggest ground state structural dynamical instability. The structure has no negative-energy phonon branches under 10 GPa stress. From band structure and density of state analysis, the structure behaves metallically under hydrostatic pressure. Also, the structure has maximal ultra-violet conductivity and absorption. The absorption coefficient, conductivity, and loss function plots show uniform patterns at all pressures. As pressure rises, these graphs' peaks blue shift.