Mechanism of Cobalt Aluminate Spinel Formation in Solid State Reaction.

摘要

Solid state reactions of cobalt oxide and aluminum oxide to form cobalt aluminate spinel at 1200-1400C were investigated by techniques of transmission electron micrography and thermogravimetry. Thin composite oxide films were used to study the nature and mechanism of the interface reactions. The reaction kinetics between the equimolar amounts of mixed oxide powders were determined. The reaction rate was expressed by Jander's diffusion equation and was controlled by counterdiffusion of cobalt and aluminum ions. Comparison of theoretical and experimental values of diffusion coefficient in the spinel layer was discussed. (Author)