AUGER ELECTRON SPECTROSCOPY STUDY OF INITIAL STAGES OF OXIDATION IN A COPPER -19.6-ATOMIC-PERCENT-ALUMINUM

Auger electron spectroscopy was used to examine the initial stages of oxidation of a polycrystalline copper - 19. 6 a/o-aluminum alloy. The growth of the 55-eV "aluminum oxide" peak and the decay of the 59-, 62-, and 937-eV copper peaks were examined as functions of temperature, exposure, and pressure. Pressures ranged from 1x10 to 5x10 - 4 torr of 02. Temperatures ranged from room temperature to 7000 C. A completely aluminum oxide surface layer was obtained in all cases. Complete disappearance of the underlying 937-eV copper peak was obtained by heating at 7000 C in 02 at 5x10 - 4 torr for 1 hr. Temperature studies indicated that thermally activated diffusion was important to the oxidation studies. The initial stages of oxidation followed a logarithmic growth curve a pre-logarithmic factor x o 0. 119 (thickness in arbitrary units) and a time factor of 7T = 0 . 129 sec. Auger electron spectroscopy was used to examine the initial stages of oxidation of a polycrystalline copper - 19. 6-atomic-percent-aluminum alloy. The growth of the 55-eV "aluminum oxide" peak and the decay of the 59-, 62-, and 937-eV copper peaks were examined as functions of temperature, exposure, and pressure. Pressures ranged from 1x10 - 7 to 5x10 - 4 torr of 0 2 . Temperatures ranged from room temperature to 7000 C. A completely aluminum oxide surface layer was obtained in all cases. Complete disappearance of the underlying 937-eV copper peak was obtained by heating at 7000 C in oxygen at 5x10 - 4 torr for 1 hour. Temperature studies indicated that thermally activated diffusion was important to the oxidation studies. The initial stages of oxidation followed a logarithmic growth curve x = x 0 In 1 + ) with a pre-logarithmic factor, x 0 , of 0. 119 (thickness in arbitrary units) and a time factor, 70, of 0. 129 second.