Authors: D Saikia J P Borah
Publish Date: 2017/02/15
Volume: 28, Issue: 11, Pages: 8029-8037
Abstract
We have synthesized diluted magnetic semiconducting nanoparticles of undoped and Ni doped ZnS by varying Ni concentration via chemical coprecipitation technique The formation of cubic zinc blend structure and the incorporation of Ni into ZnS lattice are confirmed by the Xray diffraction XRD measurements Rietveld refinement of the structural parameters shows a reasonable GOF value Transmission electron microscopy result reveals the crystalline nature of the ZnS nanocrystal with an average dspacing of 31 Å and also clarifies that the average particle size of the nanoparticles is in the range of 3–7 nm which are consistence with the XRD results UV–visible measurement depicts that the band gap of the Ni doped ZnS nanoparticles is higher than that of bulk ZnS which is a result of the quantum confinement effect Room temperature photoluminescence PL spectra shows the green emission in Ni doped ZnS nanoparticles which is the characteristic 3T2–3A2 transition of Ni2+ ion and also depicts the PL quenching effect at higher Ni concentration Fourier transform infrared measurements show different stretching and vibrational modes and also show the resonance interactions of the sulphide ions Raman analysis reveals different phonon modes of ZnS and confirms the defect states Room temperature magnetic measurements demonstrate the ferromagnetic behavior in undoped ZnS nanoparticles due to the presence of structural defects Systemic studies on the magnetic properties revels that all the doped ZnS nanoparticles exhibit the carrier mediated ferromagnetism and the saturation magnetization increases with increasing concentration of Ni
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