An-Najah Staff

The structural, electronic and magnetic properties of half-Heusler CoFeIn and full-Heusler Co2FeIn alloys have been investigated by using the state of the art full-potential linearized augmented plane wave (FP-LAPW) method. The exchange-correlation potential was treated with the generalized gradient approximation (PBE-GGA) for the calculation of the structural properties, whereas the PBE-GGA+U approximation (where U is the Hubbard Coulomb energy term) is applied for the computation of the electronic and magnetic properties in order to treat the “d” electrons. The structural properties have been calculated in the paramagnetic and ferromagnetic phases where we have found that both the CoFeIn and Co2FeIn alloys have a stable ferromagnetic phase. The obtained results of the spin-polarized band structure and the density of states show that the CoFeIn alloy is a metal and the Co2FeIn alloy has a complete half-metallic nature. Through the obtained values of the total spin magnetic moment, we conclude that in general, the Co2FeIn alloy is half-metallic ferromagnet material whereas the CoFeIn alloy has a metallic nature.

The structural properties of scandium nitride compound (ScN) in the rocksalt phase (RS) have been calculated using the full potential linearized augmented plane wave (FP-LAPW) method within the local density (LDA), Predew-Burke-Ernzerhof (PBE-GGA), Wu-Cohen (WC-GGA), and Engel-Vosko (EV-GGA) approximations. The influence of electron correlation has also been considered in calculating the electronic structure of RS-ScN within the LDA+U ^SIC, PBE-GGA+U ^SIC, WC-GGA+U ^SIC, and EV-GGA+U ^SIC approximations. For the system of interest, the calculations show that EV-GGA and PBE-GGA approximations give more accurate values for the lattice parameter (a 0) and bulk modulus (B 0) than LDA and WC-GGA approximations. The calculations also show that EV-GGA+U ^SIC approach improves the description of the electron structure of RS-ScN than LDA+U ^SIC, WC-GGA+U ^SIC and PBE-GGA+U ^SIC methods. The energy band gap of RS-ScN within EV-GGA+U ^SIC scheme is found to be 1.09eV. This value is in excellent agreement with the experimental value of about 0.8-1.6eV.

The structural properties of scandium nitride compound (ScN) in the rocksalt phase (RS) have been calculated using the full potential linearized augmented plane wave (FP-LAPW) method within the local density (LDA), Predew–Burke–Ernzerhof (PBE-GGA), Wu–Cohen (WC-GGA), and Engel–Vosko (EV-GGA) approximations. The influence of electron correlation has also been considered in calculating the electronic structure of RS–ScN within the LDA+U^SIC, PBE-GGA+U^SIC, WC-GGA+U^SIC, and EV-GGA+U^SIC approximations. For the system of interest, the calculations show that EV-GGA and PBE-GGA approximations give more accurate values for the lattice parameter (a₀) and bulk modulus (B₀) than LDA and WC-GGA approximations. The calculations also show that EV-GGA+U^SIC approach improves the description of the electron structure of RS–ScN than LDA+U^SIC, WC-GGA+U^SIC and PBE-GGA+U^SIC methods. The energy band gap of RS–ScN within EV-GGA+U^SIC scheme is found to be 1.09 eV. This value is in excellent agreement with the experimental value of about 0.8–1.6 eV.