Investigation of optical, structural, FTIR and magnetic properties of Sn substituted Zn0.98Mn0.02O nanoparticles

Zn0.98Mn0.02O and Zn0.98−xMn0.02SnxO (x=2% and 4%) nanoparticles have been successfully synthesized via sol-gel method. X-ray diffraction (XRD) confirmed the hexagonal wurtzite structure of the samples and also successful Sn doping without any secondary phases. The microstructure of ZnMnO was significantly altered where the morphology was turned from mixed plate-like structure to spherical like structure by Sn substitution which was confirmed by electron microscope images. The energy dispersive X-ray (EDX) analysis confirmed the presence of Sn and Mn in Zn-O nanoparticles. The observed narrowing of energy gap (red shift) from 3.85 eV (Sn=0%) to 3.66 eV (Sn=4%) was discussed based on size effect and generation of free carrier concentrations. The improved optical properties of Sn-Zn-Mn-O evidenced for developing opto-electronic devices with better conversion efficiency. The shift of lattice mode (position) around 527-548 cm−1 and the change in shape of the band demonstrated the presence of Sn in Zn-Mn-O. The decrease of UV emission intensity and increase of defect related blue and green emissions indicated the possible generation of white light sources and display devices. The superior magnetic property of Sn doped Zn0.98Mn0.02O was explained by the intrinsic exchange interaction between Zn/Mn/Sn ions through the defects induced by Sn.