Co-doped ZnO single-crystalline nanorods were prepared by the modified micro-emulsion route. The crystalline structure, morphology, oxygen vacancy emission, and hysteresis loop at low temperature and room temperature of as-prepared materials were characterized by X-ray diffraction, transmission electron microscopy, photoluminescence spectra, and magnetic measurements, respectively. The nanorods were 60-90nm in diameter and about 2μm in length. X-ray diffraction data, transmission electron microscopic images and selected area electron diffraction patterns confirmed that the materials synthesized in optimal conditions were ZnO:Co single crystalline solid solution without any impurities related to Co. Magnetic measurements showed that different surfactants as template in synthesis process result in ferromagnetism and paramagnetism in Zn 0.95Co0.05O nanorods. The photoluminescence spectra showed that the ferromagnetic samples exhibited strong oxygen vacancy emission whereas in the paramagnetic samples the oxygen vacancy emission was absent, indicating that the defects may stabilize ferromagnetic order in diluted magnetic semiconductors, resulting in high-temperature ferromagnetism.Effect of Oxygen Vacancy on Magnetism of ZnO:Co Single-Crystalline Nanorods. Che, P., Liu, S., Sun, C., Zhou, H., Li, W., Tang, J.: Journal of Magnetism and Magnetic Materials, 2013, 327, 28-30