The parabolic rate constant for the solid‐state reaction of was measured at temperatures between 1483 and 1688 K in air and at 1695 K in oxygen pressures between 2.1 × 10⁴ and . According to Wagner's theory, the diffusion coefficient of in was evaluated using the parabolic rate constant and the standard Gibbs energy change of the reaction. The oxygen pressure dependence of the diffusion coefficient is given by where is the activity of and is the oxygen pressure. The temperature dependence of the diffusion coefficient of lanthanum ion in is given by (at higher , e.g., at 1695 K).

Oxidation behavior of ceramic matrix composites dispersed with metallic particles is discussed to establish materials design for high-temperature applications. Oxidation kinetics of ceramic matrix composites dispersed with metallic particles is understood from the viewpoint of the diffusion properties and defect chemistry of matrix oxides. High-temperature oxidation of Ni(p)/partially stabilized zirconia, Ni(p)/Al 2 O 3 and Ni(p)/MgO was described as examples.