1987 Volume 51 Issue 4 Pages 338-341
Oxidation of Sm, Eu and Gd was investigated by conventional weight gain tests and SEM with small plates (1 mm×1 mm×0.2 mm) and by the measurement of resistivity of metal thin films in oxygen atmosphere at elevated temperatures. The temperature at which the oxidation of Sm thin film (thickness: 1 μm) began was 780 K and was close to that for the oxidation of Sm metal plate. Thin films of Eu and Gd (thickness: 1 μm) oxidized abruptly above about 400 K. However, the oxidation temperatures of the metal plates differed largely from one another. The reaction kinetics for Sm was parabolic and the others obeyed a linear oxidation law. The values of the activation energy of oxidation were compared with those reported in the literature. Further, the state of surface oxide was briefly discussed on the basis of the SEM photographs of cross sections of the oxidized Eu and Gd plates.
