Influence of transition metals dopant type on the structural, optical, magnetic, and dielectric properties of ZnS nanoparticles prepared by ultrasonication process

Abstract

Undoped and (Ni, Co, and Mn)-doped ZnS nanoparticles (NPs) are successfully synthesized by a sonochemical-assisted co-precipitation technique. XRD patterns reveals the incorporation of dopant ions by substitution of Zn ions. Ni ions induce growth rate enhancement and the increase of crystallite size, whereas Co and Mn ions slow down the growth rate and caused the decrease of the corresponding crystallite size. The UV–visible absorption spectra exhibit a decrease in the optical band gap for all doped samples. The photoluminescence spectra of Co- and Mn-doped ZnS NPs show an improvement in the visible-light, whereas Ni-doping results in a slight decrease in the emission intensity allover spectral range. The room-temperature ferromagnetism of ZnS NPs is strongly improved by Ni- and Co-doping and slightly enhanced by Mn-doping. The AC conductivity of ZnS NPS is enhanced by Ni- and Co-doping and decreased by Mn-doping in the frequency range from 2 kHz to 1 MHz.