The theoretical research of the physical properties of LnAuSb (Ln=La, Ce, Pr) compounds

In this thesis, LaAuSb, CeAuSb and PrAuSb compounds were examined theoretically. These compounds are known to form crystalline in hexagonal (space group no: 194, P63/mmc). The obtained results by calculating the structural, electronic and vibrational properties of the compounds were compared with the available experimental data. Some physical properties, experimentally difficult to obtain and costly, were also released. From the electronic band structure calculations, it was determined that these compounds had metallic character. In addition, charge densities were interpreted and detailed information was given about bond structures. The second order elastic constants of the compounds were calculated and found to be lay down mechanical stability conditions. These constants were used to evaluate the polycrystalline properties (volume, shear, Young modules, Poisson's ratio, Debye temperature, ambient sound velocities) and their anisotropy of the materials. It was determined that these compounds show soft and ductile nature. Also, the phonon distributions and phonon density of states of the compounds were visualized by supercell approximation and density functional perturbation theory. All considered materials were found vibrationally stable.