Role of Cu and Mn dopants on d0 ferromagnetism of ZnS nanoparticles

Abstract

This article deals with the structural, optical, morphological and magnetic properties of Cu, Mn and (Cu,Mn) co-doped ZnS nanoparticles synthesized by chemical precipitation method. The structural analysis confirmed the purity and face-centered cubic structure of ZnS. The crystallite size was found to decrease with dopants. The other parameters such as microstrain, dislocation density, stacking fault, x-density and surface area also increase with the dopant. The energy gap calculated from UV–Vis absorption spectra is found to vary between 3.85 and 4.10 eV for ZnS and (Cu,Mn) co-doped ZnS nanoparticles, respectively. The photoluminescence spectrum reveals that the intensity of both UV and visible emission is suppressed by the Cu and Mn dopants. Fourier transform infrared spectroscopy study confirms the formation of ZnS and the substitution of Mn and Cu ions. The microstructural study concludes that the size of the particles is less than 14 nm. The vibrating sample magnetometer results depict that the ZnS, and Cu doped ZnS are ferromagnetic whereas Cu, and (Cu,Mn) co-doped ZnS are weak ferromagnetic. EPR spectrum also confirmed the d0 ferromagnetism of ZnS and ferromagnetism of Cu, Mn and (Cu,Mn) co-doped ZnS samples.