Structural, morphological, opto-luminescence and magnetic behavioral variations of Co-ZnS hybrid nanoparticles

Co-doped ZnS hybrid nanoparticles were synthesized by chemical precipitation method. XRD peaks were shifted toward higher angle with increasing dopant concentration, which were corresponding to the structural changes in the presence of Co. Chemical compositions of the prepared materials were confirmed by EDAX. High-resolution transmission electron micrographs (HRTEM) revealed finger print appearance and are corresponding to miller indices of ZnS, confirming the quantum size of the prepared nanoparticles. The particle size was found to vary from 2 to 4 nm. The results of the selected area electron diffraction (SAED) are in agreement with the XRD results. The peaks observed between 616 and 1103 cm(-1) are ascribed to cobalt and sulfur bond. The higher band gap energy obtained for the prepared nanoparticles as compared to bulk ZnS from the DRS spectra revealed quantum confinement. The intensity of the photoluminescence (PL) was found to increase with the decrease in crystallite size. The observe increase of the PL intensity is due to quantum size effect. The magnetization (M-H curve) measured at room temperature exhibited saturated hysteresis loop for higher Co concentration indicating the ferromagnetic nature of the prepared nanoparticles.