Investigation on electronic and structural properties of some rare earth and transition metal compounds

Abstract

First-principle computations on structural and electronic properties of cubic rare-earth REIr3 (Gd, Tb and Ho) and ErX3 (X= Ga, In and Sn) intermetallic compounds have been accomplished using the full-potential linearized augmented plane wave method within the framework of density functional theory. For the exchange correlation we used LSDA+U approach in account of the strong on-site Coulomb repulsion between the localized RE-4f states. Calculated ground state properties such as lattice constant (a0) and other parameters with exchange correlation functional are found compatible with the experimental results. The calculated lattice parameter is found to be consistent with the experimental results. The calculated magnetic moments predict the ferromagnetic behavior of these compounds. The electronic and bonding properties have been solved in terms of band structure, DOS and charge density plots. These results confirm the metallic nature of these compounds. The bonding appearances of these compounds have also been interpreted from charge density plots. The elastic constants, shear modulus and Cauchy s pressure are computed and they disclose that GdIr3 and TbIr3 compounds are ductile in description while HoIr3 shows brittle character. The electronic properties have been determined in terms of band structures, total and partial DOSs and Fermi surfaces, which demonstrate the metallic behavior of all the compounds. Also the effect of Hubbard potential on this is discussed in detail. The bonding descriptions of these compounds have also been evaluated from charge density difference plots, which display the presence of metallic and mixed covalent-ionic bonding. The determined magnetic moments explain the ferromagnetic behavior of these compounds. we have attempted to predict the presence of structural phase transition in these nitrides from zinc- blende (B3) to rock- salt (B1) structure when put under pressure using a improved interaction potential model (IIPM), which includes Coulomb interactions, three body interaction