In this study, undoped ZnO and Co-doped ZnO (Zn₁-ₓCoₓO (x=0, 0.01, 0.03 and 0.05)) diluted magnetic semiconductor (DMS) nanoparticles were synthesized using coprecipitation method. The structural, optical and magnetic properties of the Co-doped ZnO samples annealed at 600oC were characterized by X-ray diffractometer (XRD), Scanning electron microscope (SEM), UV-visible absorption spectroscopy and Vibrating sample magnetometer (VSM). The average crystalline size was calculated using Debye-Scherrer’s formula. The particle size was found to be in the range of 39 to 50 nm. The X-ray diffraction studies revealed that the synthesized Co doped ZnO nanoparticles have single phase wurtzite structure with no signature of secondary phases. However, the position of diffracted peaks slightly shifted towards lower (2θ) angles. SEM micro-image confirmed the presence of spherical Zn₁-ₓCoₓO nanoparticles. VSM measurements show the hysteresis loop with high coercive value at room temperature which confirms the ferromagnetic property of the samples. The presence of ferromagnetic behavior is due to intrinsic coupling among the atoms of doped materials.
