First principle study of structural, electronic, mechanical, dynamic and optical properties of half-Heusler compound LiScSi under pressure

• Published in: Phase transitions Vol. 91; no. 12; pp. 1206 - 1222
• Main Authors: Ciftci, Yasemin O., Evecen, Meryem
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 02.12.2018; Taylor & Francis Ltd
• Subjects: Ab-initio calculations; Bulk modulus; Charge density; Density; Density functional theory; Density of states; Dielectric properties; Dispersion curve analysis; Dynamic stability; Elastic analysis; Elastic properties; electronic structure; Equations of state; First principles; Half-Heusler; Lattice parameters; Mathematical analysis; Modulus of elasticity; Optical properties; Physical properties; Poisson's ratio; Refractivity; Shear modulus; Ternary
• ISSN: 0141-1594; 1029-0338
• DOI: 10.1080/01411594.2018.1515433

In this study, several physical properties of LiScSi compound with MgAgAs phase were investigated via the plane-wave pseudo-potential technique in density functional theory (DFT). The calculated total energy-atomic volume was fitted to the Murnaghan equation of state in order to obtain bulk modulus, their first derivatives and the lattice constant. These results were compared to findings of recent literature. Afterwards, the partial density of states (PDOS) and charge density differences were used to evaluate the electronic band structure of LiScSi under pressure. By analysing elastic properties (shear modulus, Poisson ratio, Young's modulus, etc.) of the material, it has been shown that MgAgAs phase of the compound is mechanically stable under pressure. Moreover, the dynamical stability of this compound is calculated by means of the phonon dispersion curves and one-phonon DOS. Finally, the optical properties and related parameters (refractive index, dielectric function, and loss function) of LiScSi were examined with subject to different pressures.