Thermal oxidation of thin films of Fe-Ni solid solutions

The oxidation kinetics of thin films of dilute Fe–Ni solid solutions (0.17, 0.54, 0.65, 0.91, and 1.87 at % Ni) on single-crystal Si substrates are studied. The oxidation rate of the films is found to decrease with increasing Ni concentration. The predominant phase in all of the oxide layers is Fe2O3 , independent of the oxidation conditions. It is shown that, at an Ni content of about 1 at %, the composition dependences of the oxide thickness, refractive index, extinction coefficient, and apparent activation energy for oxidation show extrema. The mechanism of film oxidation is discussed.