Initial results on the Ag|CdO [222] interface: Atomic scale interfacial chemistry and sequencing of ordered cadmium/oxygen planes

In this study the authors present the first APFIM results on silver/cadmium oxide interfaces produced by internal oxidation of a Ag(Cd) alloy. Internal oxidation of binary metal alloys is a well-studied phenomenon, and is based upon preferential oxidation of solute atoms (B) in a dilute A(B) alloy. Internally-oxidized silver (cadmium) alloys are used to switch medium to high currents, and have been the focus of studies of their strength and electrical properties. Previous HREM investigations of silver/cadmium oxide interfaces, produced by internal oxidation, have determined that the cadmium oxide precipitates have a cube-on-cube orientation relationship with the silver matrix, are octahedrally shaped, are bound by [222] planes, and can be truncated along <100> directions. (The lattice misfit parameter--ν = 2[(aCdO + aAg)]--between silver and cadmium oxide is 0.14.) Mader and co-workers suggest, via HREM observations, that the terminating [222]-type plane of CdO is the oxygen plane. In this paper the authors present evidence that it is possible to dissect cadmium oxide precipitates on an atom-by-atom basis, via the pulsed field-evaporation technique