TRANSMISSION ELECTRON-MICROSCOPE STUDY OF ANTIMONY-DOPED ZINC-OXIDE CERAMICS

A transmission electron microscope investigation of a ZnO powder and low-temperature air-sintered pellets with small additions of Sb2O3 was conducted in order to study the thin Sb-rich film on the surfaces of ZnO particles. This film was found to be noncrystalline at temperatures below 700-degrees-C, and partially crystalline or completely crystalline above this temperature. An oriented overgrowth of the spinel Zn7Sb2O12 was observed on the prismatic planes as well as on the basal planes of ZnO crystallites. It is shown that these coherently overgrown spinel films are responsible for the inhibition of grain growth at high temperatures.