Cu2O island shape transition during Cu-Au alloy oxidation.
In situ transmission electron microscopy observations of the oxidation of (001) Cu-Au alloys indicate that the Cu2O islands that form undergo a remarkable transformation from an initially compact morphology to a dendritic structure as growth proceeds. Correspondingly, the surface composition becomes nonuniform and the fractal dimension associated with the islands evolves from 2.0 to a stable value of 1.87, indicating a transition in the rate-limiting mechanism of oxidation from oxygen surface diffusion to diffusion of copper through the increasingly gold-rich regions adjacent to the islands.
Zhou
G-W
GW
Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Wang
L
L
Birtcher
R C
RC
Baldo
P M
PM
Pearson
J E
JE
Yang
J C
JC
Eastman
J A
JA