Structure, electronic, mechanical and optical properties of ternary YAl3C3 carbide

Abstract

The electronic structure, mechanical and optical properties of ternary yttrium aluminum carbide (YAl3C3) has been studied by first principles approach. The crystal structure and elastic properties are studied by using Vienna ab initio simulation package (VASP). An orthogonalized linear combination of atomic orbitals (OLCAO) method based on the density functional theory (DFT) is implemented to elucidate the electronic structure and optical properties of ternary YAl3C3 carbide. The YAl3C3 carbide exhibits a narrow indirect band gap, Eg=0.12eV which shows its poor metallic and/or semiconductor behavior. The effective charge (Q*) calculation reveals more charge transfer from Al-sites as compared to Y-sites which indicates dominant ionic character of Al-sites. The analysis of structure and bond order (BO) calculations show that the Al–C bonds in the basal plane are much stronger as compared to Al–C bonds along the c-axis. The Al–C bonds lying in the basal plane have main contribution into the overall stiffness of YAl3C3 carbide. The effective mass of charge carriers (electrons and holes) and inter-band optical properties (complex dielectric function and optical conductivity) are also studied which show high degree of anisotropy in YAl3C3.