Effect of Oxygen Vacancy on Half Metallicity in Ni-doped CeO2 Diluted Magnetic Semiconductor

The electronic and magnetic properties of Ni-doped CeO2 diluted amgentic semiconductor (DMS) including the effect of oxygen vacancy (V-o) with doping concentration, x = 0.125 have been calculated using FPLAPW method based on Density Functional Theory (DFT) as implemented in WIEN2k. In the present supercell approach, the XC potential was constructed using GGA+U formalism in which Coulomb correction is applied to standard GGA functional within the parameterization of Perdew-Burke-Ernzerhof (PBE). We have found that the ground state properties of bulk CeO2 compound have been modified significantly due to the substitution of Ni-dopant at the cation (Ce) site with/without VO and realized that the ferromagnetism in CeO2 remarkably depends on the Vo concentrations. The presence of Vo, in Ni-doped CeO2, can leads to strong ferromagnetic coupling between the nearest neighboring Ni-ions and induces a HMF in this compound. Such ferromagnetic exchange coupling is mainly attributed to spin splitting of Ni-d states, via electrons trapped in Vo. The HMF characteristics of Ni-doped CeO2 including Vo makes it an ideal material for spintronic devices.