Sb substitution into ZnO nano-composite: Ferromagnetic behavior

Properties of particles whose dimensions are of the nanoscale can be quite different from those of bigger dimension particles. We investigate here the effects of doping Sb5+ ions into ZnO nanorods (NR's) on the formation of magnetic moments. The pure ZnO and Sb-doped ZnO NR's were grown by the hydrothermal process. The fabricated nanorods were then studied using X-ray diffraction (XRD), ultraviolet–visible light spectroscopy (UV–vis), Scanning Electron Microscopy (SEM), Photoluminescence (PL) Spectrometer and Vibrating Sample Magnetometer (VSM) spectrometry. Substitution of Sb into the ZnO leads to the formation of a defect (SbZn+2VZn) complex state which can capture the oxygen p-orbital electrons of the oxygen atoms and form a spin polarized state. The PL was used to monitor the defect formation in the ZnO NR's when the Sb is doped in. As more Sb was doped in, the visible blue portion of the PL spectrum decreased while the visible red portion increased. Magnetization measurements (VSM) showed that the pure ZnO NR's possessed a magnetic moment which initially increased as Sb is doped in but decreased as more Sb was doped in. We obtain a value of 1.015 memu/g for the saturation magnetization of the pure ZnO nanorod.