Transition metal (Mn) and rare earth (Nd) di-doped novel ZnO nanoparticles: a facile sol–gel synthesis and characterization

Abstract

Undoped, Mn doped and Nd co-doped ZnO nanoparticles are synthesized through a facile sol–gel route. Characterization of the synthesized samples has been done by X-ray diffraction, scanning electron microscopy, FT-IR, diffuse reflectance spectroscopy, photoluminescence spectroscopy, hall measurement and vibrating sample magnetometry. Structural and vibrational studies shown hexagonal wurtzite structure of prepared ZnO samples. SEM images have revealed that the grains are hexagonal and spherical shapes for undoped and co-doped samples. The crystallite size was found in range of 43–34 nm. The value of optical band gap is calculated and it is found ~ 3.27 eV for undoped and decreased to 3.20 eV for Mn doped, Nd co-doped sample. This tuning in band gap is because of the fact that the impurity band of ZnO is merged with the conduction band. Photoluminescence study reveals that the intensity of the prepared samples is systematically reduced with the addition of Mn and Nd doping element. Hall effect measurements reveal that the conductivity of ZnO nanoparticles is increased with respect to temperature. The magnetic measurements indicate that the obtained nanostructures are found to be room temperature ferromagnetism (RTFM) with maximum value of saturation magnetization for Nd co-doped Mn:ZnO nanoparticles, i.e. 2.44 emu g−1. Thus the magnetic properties of ZnO prepared by low cost sol–gel method have been enhanced by Mn doping as well as Nd co-doping which can be used for spintronic applications. In future, similar rare earth materials could be considered for enhancing the magnetic properties of nano particles.