Effect of Grain Size on Magnetic Properties of ZnO Doped with Nickel Single Impurities

The purpose of our study is to find a suitable material to be used in spintronic applications and to find the relation between the parameters of deposition by spray pyrolysis technic (temperature, concentration of Ni doping) and the ferromagnetic properties (Curie temperature, magnetic moment). The nickel-doped zinc oxide, Zn.1-x.NixO (x = 0.01, 0.03, 0.05), and diluted magnetic semiconductors (DMSs) are synthesized by the spray pyrolysis technic. The results of The X-ray diffraction (XRD) of prepared substrates confirm the incorporation of the dopants into the ZnO lattice structure. The spin-polarized electronic properties has been found and was investigated in detail by using the density-functional theory (DFT), the local density approximation (LDA), and The Korringa-Kohn-Rostoker coherent potential approximation (KKR-CPA). As result, nickel doping brings up a half-metallic appearance due to the hybridization between the 3d state of Nickel impurities and the oxygen 2p state. The mechanism of the interatomic exchange has been explained as being a p-d double exchange.