Nickel-substituted copper oxide nanoparticles at various concentrations were synthesized by the microwave irradiation technique. The consequence of nickel doping on crystal structure, optical properties, and magnetic properties was examined by means of X-ray diffractometer, ultraviolet-visible spectrometer, Fourier transform infrared (FT-IR) spectrometer, transmission electron microscope, and vibrating sample magnetometer (VSM). X-ray diffraction analysis shows that the samples are monoclinic and their crystallite size varies from 25[Formula: see text]nm to 42[Formula: see text]nm, and lattice constant significantly increases with nickel concentration. Additional increase of nickel content (7%) decreases the lattice constant. TEM micrograph witnessed that the prepared nanoparticles were sphere-shaped and the particle distribution is in the range between 20 and 40[Formula: see text]nm. Bandgap measurement reveals that both undoped and nickel-doped copper oxides are direct bandgap semiconductor materials with bandgaps of 3.21 and 3.10[Formula: see text]eV, respectively, FT-IR spectra of the synthesized samples confirmed the nickel doping. VSM studies confirmed the ferromagnetic behavior of the synthesized samples at room temperature. The results revealed that the nickel-doped copper oxide nanoparticles synthesized via the microwave irradiation method exhibit better magnetic properties than the undoped copper oxide.
