Thermodynamic, elastic, phonon, and optical properties of LaRh2X2 (X=Al, Ga, In) superconductor: A DFT insights

LaRh 2 X 2 (X = Al, Ga, In) has a tetragonal layered structure, a family of ThCr 2 Si 2 -type low T c superconductors. For the first time, we investigated the structural, mechanical, elastic, electronic, vibrational, thermophysical, optical, and electron-phonon coupling properties of LaRh 2 X 2 using first-principles calculations based on density functional theory (DFT). The calculated structural parameters are well in agreement with available experimental outcomes, which confirms the precision of our calculations. The analysis of Born stability criteria and formation energy confirmed the mechanical and thermodynamic stability of the studied materials under the scheme, respectively. The dynamical stability of the LaRh 2 Al 2 and LaRh 2 Ga 2 and the instability associated with the structural phase transition of LaRh 2 In 2 superconductors are discussed based on the phonon dispersion curves. The calculated superconducting Eliashberg spectral function reveals an average electron-phonon coupling constant of λ ∼0.59, implying a moderate electron-phonon interaction in LaRh 2 Al 2 with an estimated T c of 2.6 K. The failure mode study manifests the ductile behavior of the studied superconductors. The anisotropic nature is seen by the various anisotropy indices. The electronic band structure and density of states reveal the metallic character. The analysis of electronic charge density mapping and Mulliken population revealed a combination of covalent, ionic, and metallic bonding. The calculated Fermi surface topologies reveal both hole-like and electron-like sheets, suggesting a multiband nature of the studied materials. The various optical and thermodynamic properties are calculated and analyzed. The analysis of refractive index speculates that the studied superconductors may be potential candidates for high-density optical data storage devices.