D.P. Rai

Ground state calculation of the electronic structure and magnetic properties of Co2VAl: a local spin density approximation with exchange correlation potential study

We performed first-principles calculations of Co2VAl to determine its electronic and magnetic properties. For this, the density functional-based full potential linearized augmented plane wave method is used. Firstly, volume optimization is done based on generalized gradient approximation to determine the equilibrium lattice parameters. To determine the impact of on-site Coulomb repulsion (U) on the electronic structure, local spin density approximation with exchange correlation potential is used. The U values are varied within reasonable limits to study the resulting effect on the physical properties of the Co2VAl system. The calculated density of states and band structure show that half-metallicity of Co2VAl depends upon the increase in U values. This study concludes that U is sensitive to the type of systems and one should not merely choose the U value randomly.

A DFT study of BeX (X = S, Se, Te) semiconductor: modified Becke Johnson (mBJ) potential

The electronic, optical and elastic properties of BeX were performed within full potential liberalized augmented plane wave method based on density functional theory (DFT). Generalized gradient approximation (GGA) and modified Becke Johnson (TB-mBJ) potential were used for exchange correlation. The mBJ gives improved band gap as compare to GGA and in close agreement with the experimental results. The present band gaps of BeS, BeSe and BeTe calculated within mBJ are 4.40, 4.0 and 2.40 eV respectively.

Electronic and magnetic properties of a full-Heusler alloy Co2CrGe: a first-principles study

The structural, electronic, and magnetic properties of Co2CrGe, a Heusler alloy, have been evaluated by first-principles density functional theory and compared with the known experimental and theoretical results. Generalized gradient approximation is used for structural study, whereas local spin density approximation is used for electronic calculation. First-principles structure optimizations were done through total energy calculations at 0 K using the full-potential linearized augmented plane wave method as implemented in the WIEN2K code.

Study of Bulk modulus, Volume, Energy, lattice parameters and magnetic moments in rare earth hexaborides using density functional theory

We have calculated the theoretical lattice parameters, Bulk modulus, volume, energy, lattice parameters and magnetic moments for RB6 (R=La, Ce, Pr and Sm) of CaB6 type crystal structure with space group Pm3m using full potential linearized augmented plane wave (FP-LAPW) method. The bulk modulus was found to be 9.56 % higher for LaB6 and 2.4% lower for CeB6 compared to the experimental results Gupta et al. [4] and Ogita et al [5], Magnetic moments for LaB6, CeB6 were found in qualitative agreement with the earlier reported results. The results based on generalized gradient approximation (GGA) were found and compared with local spin density approximation (LSDA) results for CeB6 and SmB6 as well.