Investigation of vibrational and superconductivity properties of Cr and CrC crystals using the density functional theory

Keywords: Density functional theory, transition metal (Cr), transition metal carbide (CrC), structural properties, elastical properties, electronic properties, vibrational properties, high symmetry points, superconductivity properties.In this thesis, we have investigated structural, elastical, electronic, vibrational and superconductivity properties of transition metal Cr which is crystallized in volume-centered cubic lattice and transition metal carbide CrC which is crystallized in sodium chloride structure by using the density functional theory. The density functional theory has been implemented within a generalised gradient approximation, using the Perdew-Burke-Ernzerhof method. The Kohn-Sham single-particle functions were expanded in a basis of plane waves. Self-consistent solutions of Kohn-Sham equations were obtained by sampling the irreducible part of the Brillouin zone by employing special k points. A kinetic energy cut off of 60 Ryd is used.In the introduction of this study, previous studies on these materials have been cited and we have explained the goal of this thesis. The general informations of elastical properties have been given in the second chapter. In the third chapter, density functional theory and used approximations are summarized. In the same chapter the application of density functional theory to these materials has been also explained. In the last chapter, the obtained results for structural, elastical, electronic, vibrational and superconductivity properties of transition metal (Cr) and transition metal carbide (CrC) have presented and compared wit