OLCAO based Electronic Structure Calculations and Optical Properties of Ni_3Ga Intermetallic Alloy System

Altaf Hussain ； M. Nasir Rasool ； Salman Mehmood ； M. Shakil

《Chinese Journal of Physics》 52卷6期 (2014/12) Pp. 1770-1784

https://doi.org/10.6122/CJP.20140722

並列摘要

The first-principles orthogonalized linear combination of atomic orbitals (OLCAO) method has been employed to study the electronic structure and optical properties of the Ni3Ga intermetallic alloy system. To see the effects of ordering, we have simulated the ordered (L12) and disorder models. The calculated optical conductivity of the ordered phase is rich in structures and in reasonable agreement with the experimental data, while the conductivity spectrum of the disordered phase shows a single broadened peak. It is found that the average charge transfer from Ga to Ni in the ordered phase was greater (0.376 electrons per atom) as compared to the disordered phase (0.234 electrons per atom). The localization index (LI) calculations show that in case of the ordered phase there were localized states present below as well as above the Fermi-level. Localization of states is also present in the disordered phase, but both the models have shown different behavior. Other results on the band structure, density of states, and dielectric functions have also been discussed and described in detail.