Effect of Mn-adding on microstructure, optical and dielectric properties Zn0.95Al0.05O nanoparticles

Abstract

Pure ZnO and Zn0.95-xAl0.05MnxO (x = 0, 1, 3, 5) nanoparticles (NPs) were successfully produced through co-precipitation method. The doped ZnO nanoparticles were characterized by using X-ray diffraction (XRD), Williamson-Hall plot (W–H Plot) and field emission electron microscope (FESEM) analysis. The XRD patterns revealed that all samples exhibit crystalline hexagonal (wurtzite) structure of the ZnO NPs. The change in lattice parameters (a, c), preferential crystalline orientation for Mn doped samples, change in bond length and micro-strain after doping indicate successful incorporation of Mn2+ in Al-doped ZnO NPs. Further, the increase in average crystallite size directed the improvement in the crystalline nature. FESEM was used to study the morphological analysis of pure and doped ZnO NPs. UV Vis spectroscopy results indicate that the optical transmission improved in the visible region and band gap decreases as a result of doping. The improvement in the dielectric loss due to Mn content doping was observed and is associated with increase in the number of defects. The decrease in ac conductivity (σac) with Mn content is related with increase amount of defects.