Optical and magnetic studies on Gd doped ZnO nanoparticles synthesized by co-precipitation method

Gadolinium (Gd) doped zinc oxide (ZnO) nanoparticles (NPs) with hexagonal wurtzite structure was synthesized via a co-precipitation method. The structural properties of synthesized pure and Gd doped ZnO NPs were investigated by X-ray diffraction analysis and it showed smaller crystallite size for pure than Gd doped ZnO. HRSEM analysis revealed spindle like morphologies for the synthesized NPs. Optical properties of the nanoparticles were investigated by photoluminescence study and it revealed band edge emission for all synthesized materials with additional emissions in visible region due to the presence of vacancy and interstitial defects. FTIR provides the functional characteristics of pure and Gd doped ZnO nanoparticles. XPS measurement revealed the composition of nanostructures. Room temperature magnetic measurement was investigated using a vibrating sample magnetometer and showed weak ferromagnetism in Gd doped ZnO NPs, which is switched into super paramagnetism due to the further increase of Gd concentration in ZnO matrix.