Surfactant mediated synthesis of ZnO nanospheres at elevated temperature, and their dielectric properties

Abstract

ZnO colloidal spheres were prepared using a simple surfactant mediated approach via a two-stage reaction process, involving the synthesis of nanoparticles and the assembly of the nanoparticles to obtain nanospheres. The present work pointed out a simple and 'green' way of converting ZnO nanoparticles into ZnO nanospheres. The structural properties and the crystalline phase of the synthesized nanospheres were characterized by transmission electron microscopy (TEM), scanning electronic microscopy (SEM), and powder X-ray diffraction (XRD). The morphology of the colloidal ZnO nanosphere observed at high resolution showed a nanocrystalline substructure, and XRD indicated the hexagonal phase of zinc oxide with a high purity. The dielectric properties were studied over a frequency range of 1 Hz-1 MHz at room temperature, and in the framework of complex dielectric permittivity and complex electric modulus formalisms. The evolution of the complex dielectric permittivity as a function of frequency at room temperature was investigated