Thermodynamic Analysis on Preparing Doped Zinc Oxide Varistor Ceramic powders by Coprecipitation Process

Based on the thermodynamic analysis of Men+ (Zn2+, Cr3+ , Mn2+, Sb3+, Bi3+, Co2+)-NH3CO2---H2O systems, the curves about lg[M]T-pH of Mn+-NH3-CO32--H2O systems were obtained.It shows that the optimal pH is 7.0 to prepare doped zinc oxide varistor ceramic powders bycoprecipitation process, and the precipitants are NH4HCO3 and NH3.H2O.