Oxidation of Cobalt Metal

High‐Temperature Oxidation

“…The predictions of Wagner's theory for n-type and p-type oxides have been extensively examined by several workers [120][121][122][123][124][125][126][127][128][129]. For many systems, the obtained rate constants are generally several orders of magnitude larger than those which one would calculate from lattice diffusion data from Eq.…”

Full transition from metal to ceramic by direct oxidation of metallic cobalt powder

“…Co 3 O 4 is stable in atmospheric air below 1164 K. Above this range Co II [Co III ] 2 O 4 is reduced to Co II O. By means of inert markers of radioactive Pt, Carter et al [17] show that Co-metal oxidizes by outward diffusion of cobalt atoms through the oxide. Similarly above 973 K, the rate of oxidation is controlled by the diffusion of cobalt cations through the oxide layer.…”

“…Similarly above 973 K, the rate of oxidation is controlled by the diffusion of cobalt cations through the oxide layer. In fact both CoO and Co 3 O 4 oxides have the capability to coexist at 973 K [16][17][18][19][20][21].…”

Quantitative Prediction of Voids Formation in a Growing Cobaltous Oxide Scale at 1373 K

“…[11][12][13][14][15][16][17] The growth of CoO scales follows parabolic behavior, which is mainly determined by the diffusion of cobalt ion. CoO is also known as a typical metal deficient p-type semi-conducing oxide with metal ion vacancy as a predominating defect.…”