Effect of Mg doping on dielectric properties of ZnO nanoparticles synthesized by microwave-assisted combustion route

Abstract

The primary aim of this research work is to study the dielectric properties of nanoscale ZnO and Mg-doped ZnO nanoparticles (NPs). The microwave-assisted combustion technique was used to synthesize ZnO and Mg-doped ZnO NPs (2, 4, and 6 atomic % of Mg). XRD (X-ray diffraction), FTIR (Fourier transform infrared) and SEM (Scanning electron microscope) methods were used to characterize the materials. From the XRD pattern, the phase confirmation and crystallite size of ZnO and Mg-doped ZnO NPs were estimated. The study of dielectric properties such as dielectric loss and permittivity, impedance and AC conductivity were observed in the range of frequency (1–106 Hz). The permittivity of ZnO and 6% Mg-doped ZnO showed an enhanced dielectric property than other doped materials at higher frequency. The additional mobile carriers added to the material as a result of raising the percentage of doping resulted in an increase in the material's dielectric loss. The hopping and tunnelling mechanism, which may be attributed to the migration of electrons into the conductive network formed by the crystallites of 6% Mg-doped ZnO and ZnO NPs, caused progressively increase in the values of AC conductivity of doped nanoparticles as the frequency range was increased. The impedance (real and imaginary) was decreased with increase in the amount of Mg (in terms of atomic %).