Role of grain boundaries on the electrical properties of ZnO–Ag nanocomposites: an impedance spectroscopic study

Abstract Nanoparticles of ZnO were prepared by chemical arrested precipitation and those of silver were prepared by a reduction method. The average particle size was determined from X-ray line broadening. The ac electrical response of the consolidated ZnO–Ag nanocomposites was studied using impedance spectroscopy. The equivalent circuit parameters were determined by computer simulation of experimental data. The grain and grain boundary contributions to the conductivity were determined. The variation in the conductivity of nanocomposites in comparison with that of nanophase ZnO was attributed to the formation of Ag 2 O, the presence of which was confirmed by X-ray diffraction.