Determination of Magnetic and Electronic Properties of Co/Ni Substituted Li2O: An Ab-Initio Study

This chapter focuses on the magnetic properties of Co/Ni substituted Li2O and in this work, we investigated the electronic and magnetic properties of Co/Ni substituted Li2O using the first-principles method. The important issue addressed in this work is the possibility of half-metallic property in Li2O with Co/Ni atom substitution. Magnetic materials based on transition metals such as cobalt (Co) and nickel (Ni) and their chemical binary compounds are extremely important because of their potential applications in optical filters. We have investigated the magnetic and electrical characteristics of Co/Ni substituted Lithia (Li2O) using ab-initio calculations based on density functional theory (DFT). Utilizing the Vienna Ab-initio Simulation Package (VASP), calculations were carried out. We have performed calculations for Li1.875Co0.125O and Li1.875Ni0.125O compounds which correspond to the replacement of one Li atom by one Co/Ni atom in the supercell which contains 24 atoms. We find from our calculations that the lattice parameter of the substituted compound is slightly low when compared to that of the parent compound. In order to investigate the possibility of magnetic order in these compounds, the spin-polarized and non spin polarized calculations are carried out. From the calculated total energies of the ferromagnetic and nonmagnetic phases of these compounds, we have found that the ferromagnetic phase is stable over the nonmagnetic phases. Our calculation shows that a single Co/Ni atom substitution can induce dilute magnetic semiconducting property in Li2O. We have observed from our calculations, magnetically stable phases and large values of the magnetic moments in these compounds and it suggests that these compounds may be useful materials for semiconductor spintronics applications.