Solvothermal synthesis and magneto-optical properties of Zn1-xNixO hierarchical microspheres

Zn1-xNixO (x=0-0.25) hierarchical microspheres were synthesized via a solvothermal process in ethylene glycol. The magnetic microspheres were characterized by X-ray powder diffraction, field-emission scanning electron microscopy, energy-dispersive X-ray spectra, X-ray photoelectron spectroscopy, room-temperature photoluminescence spectra, and vibrating sample magnetometer. The as-prepared samples take on a well-defined spherical architecture following the processes of spontaneous aggregation and localized Ostwald ripening. Dependence of the magnetization and morphology on Ni2+ content was observed. Magnetic hysteresis loops reveal that the Ni-doped ZnO microspheres exhibit ferromagnetic loops at room temperature. - Research highlights: → Studying the magneto-optical properties of Zn1-xNixO synthesized by a solvothermal method. → Samples were obtained with different morphology and magnetic properties by changing Ni doping concentration. → Room-temperature ferromagnetism of the as-synthesized microspheres was demonstrated in detail.