Room temperature ferromagnetic behavior of nickel-doped zinc oxide dilute magnetic semiconductor for spintronics applications

The multifunctional zinc oxide (ZnO) nanoparticles were economically grown through a simple co-precipitation technique. Ni-doped (1, 3, and 5 wt%) ZnO nanoparticles were also grown to comprehend their influence on the ferromagnetic property of the ZnO, especially at room temperature. The structural and surface morphological features of the prepared nanoparticles were studied through X-ray diffraction (XRD) and Scanning electron microscopy (SEM) techniques, respectively. Diffused reflectance, Photoluminescence, and Fourier transform infrared spectroscopic analyses were also carried out to understand the consequence of Ni doping on the ZnO nanostructure. The secondary phase formations such as NiO and NiO2 elucidate the solid solubility limit of three percent of nickel in the ZnO matrix. Size-strain analysis was performed to evaluate the crystallite size and apparent strain values. An increase in the agglomeration of particles is evidenced by SEM micrographs with an increase in the Ni doping percentage. The bandgap measurements showed a redshift from 3.25 to 3.18 eV for the Ni-doped nanoparticles. Photoluminescence study reveals the existence of lattice defects including interstitials and vacancies in the synthesized nanostructures. The vibrating sample magnetometer studies divulge that 3% Ni-doped ZnO nanoparticles show an intense ferromagnetic property at room temperature. These experimental observations manifested that the Ni-doped ZnO nanoparticles are potential candidates for spintronics device applications.