Synthesis of Ceramic Powders Based on Manganese, Cobalt and Nickel Oxides

Mn x Co y Ni z O t ceramic powders were prepared by mixing and heat treating the oxides at temperatures in the 1200-1300 °C range for thermistor fabrication. Slurries containing the powders dissolved in water with organic binder and deflocculant were atomized in a spray dryer to get fine and homogeneous powder particles for pressing and sintering large quantities of pellets. The distribution of particle size of powders was determined by laser scattering, the density of the sintered pellets by hydrostatic (Archimedes) technique, and the electrical behavior in the room temperature-200 °C by a two-probe method. The results show that the synthesis processing and the homogenization by spray dryer are important for the fabrication of large quantities of similar ceramic thermistors with narrow distribution of electrical response.