High Temperature Oxidation Mechanism of CoO to Co3 O 4

Growth of layers on the (100) surface of single crystal was investigated in air at 700° and 800° C. These layers were of duplex structure due to simultaneous inside and outside growth. Measurements on the position of inert gold markers demonstrated that cobalt migration outward in was the dominant diffusion mechanism. The oxidation kinetics were parabolic; the parabolic rate constant at 800°C was used to obtain an estimate of for the self‐diffusion coefficient of cobalt in .