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In the present work, mixed structure Zn(S,O) nanoparticles have been synthesized using solution based chemical coprecipitation technique. Two different zinc sources (Zn(CH 3 COO) 2 ·2H 2 O and ZnSO 4 ·7H 2 O) and one sulfur source (CSNH 2 NH 2 ) have been used as primary chemical precursors for the synthesis of the nanoparticles in the presence and absence of a capping agent (EDTA). The structural, morphological, compositional and optical properties of the nanoparticles have been analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Fourier transmission infra-red (FT-IR) and UV-Visible (UV-Vis) spectroscopy. XRD revealed the formation of mixed phases of c-ZnS, h-ZnS and h-ZnO in the synthesized nanoparticles. The surface morphology was analyzed from SEM micrographs which showed noticeable changes due to the effect of EDTA. EDX analysis confirmed the presence of zinc, sulfur and oxygen in Zn(S,O) nanoparticles. FT-IR spectra identified the presence of characteristic absorption peaks of ZnS and ZnO along with other functional group elements. The optical band gap values were found to vary from 4.16 eV to 4.40 eV for Zn(S,O) nanoparticles which are higher in comparison to the band gap values of bulk ZnS and ZnO. These higher band gap values may be attributed to the mixed structure of Zn(S,O) nanoparticles.

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CdS nanoparticles are synthesized by a simple chemical coprecipitation technique using glucose as a capping/complexing agent and their structural, morphological, electrical and magnetic properties are studied. X-ray diffraction results reveal the pure phase formation of CdS nanoparticles along with a wurtzite structure. The interaction of the glucose with CdS nanoparticles is evident from the distinct absorption bands and peaks in the Fourier transform infrared spectra. Field effect scanning electron microscope and high resolution transmission electron microscope images depict weakly aggregated spherical nanoparticles of size ~2- 20 nm. The selective area electron diffraction pattern exhibits well-resolved diffraction rings representing the polycrystalline nature of the nanoparticles. The optical band gap has been calculated using Tauc’s plot and found to be 2.58 eV, which is higher than the band gap of the bulk phase wurtzite CdS. The existence of the excitonic peak and the blue-shift in the absorption threshold confirm the quantum confinement in the synthesized nanoparticles. The temperature dependence of d. c. conductivity is studied and observed a linear response through current-voltage characteristics. Weak ferromagnetism is also observed in the synthesized CdS nanoparticles irrespective of the diamagnetic nature of CdS in bulk form. The observation of weak ferromagnetism in the synthesized nanoparticles proposes them as a potential candidate for diluted magnetic semiconductors.