Room temperature ferromagnetism in Mn-doped ZnS nanocrystalline thin films grown by sol-gel dip coating process

Nanocrystalline Zn1-xMnxS (x = 0.00, 0.01, 0.02, 0.03, 0.05, and 0.1) thin films having different Mn content were grown by the sol-gel dip coating process. The effect of Mn content on the structural, optical and magnetic properties of Zn1-xMnxS nanocrystalline thin films were investigated. X-ray diffraction results showed the presence of single hexagonal phase corresponding to ZnS with a preferred orientation along the ZnS (002) hexagonal plane direction without any detectable secondary phase, suggesting the incorporation of Mn ions into the ZnS lattice. Scanning electron microscope revealed the surface of the nanocrystalline films to be homogeneous and dense and the grains of the film surface were randomly scattered. In ultraviolet-visible measurements, the band gap energy corresponding to the absorption edge estimated were found to be 3.59-3.23 eV depending on the Mn doping ratio. Magnetic measurements showed that a paramagnetic behavior at 5 K and ferromagnetic behavior at 300 K.