34th International Field Emission Symposium / 34ème Symposium International d'Emission de Champ

J. Phys. Colloques 48 (1987) C6-505-C6-510
DOI: 10.1051/jphyscol:1987683

INITIAL STAGES OF OXIDATION OF COPPER AND COPPER-IRON ALLOY

K. Hono¹, T. Sakurai² et H. W. Pickering<sup>3

1</sup>  Department of Materials Science Engineering, The Pennsylvania State University, University Park, PA 16802, U.S.A.
²  The Institute of Solid State Physics, The University of Tokyo, Roppongi, Minato-ku, Tokyo 106, Japan
³  Department of Materials Science & Engineering, The Pennsylvania State University, University Park, PA 16802, U.S.A.

Abstract
The initial oxidation stages of copper and copper-iron alloys have been studied by the Atom Probe Field Ion Microscope (AP-FIM). The depth profiles of copper oxide formed in-situ were successfully determined. The composition of the oxide was close to the value of Cu₂O, but a large concentration fluctuation was found. The interface between the oxide and the metal was found to be diffuse, the width of which was approximately 2 nm. Annealing the supersaturated Cu-1.2at%Fe alloy tip in-situ at 1000 K in UHV caused enrichment of the surface in iron atoms due to heterogeneous precipitation. No indication of surface segregation was found in Cu-0.06at%Fe or aged Cu-1.2at%Fe alloys. In-situ oxidation of the supersaturated Cu-1.2at%Fe alloy led to the formation of both external and internal oxides of iron.