The oxidation of metal-capped Co cluster films under ambient conditions.
We report on the unexpected deterioration under ambient conditions of films of Co clusters capped with relatively thick (>100 nm) Cu (or Ti) layers deposited by either thermal evaporation or by radiofrequency sputtering. The magnetic character of the clusters, prepared by gas-phase condensation, allows monitoring the oxidation of the samples through the decay of the saturation magnetization, which takes place on a timescale of days. By contrast, diluted (<10 at.%) cluster-assembled granular Co:Cu films, prepared by co-deposition of the Co clusters with a Cu vapour, are perfectly stable under ambient conditions. We tentatively explain the oxidation of the cluster films as stemming from their very high porosity.
De Toro
J A
JA
Departamento de Física Aplicada, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain. joseangel.toro@uclm.es
Andrés
J P
JP
González
J A
JA
Muñiz
P
P
Riveiro
J M
JM
D003035:Cobalt / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008567:Membranes, Artificial; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010084:Oxidation-Reduction; D010316:Particle Size; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
D046911:Macromolecular Substances; D008567:Membranes, Artificial; D003035:Cobalt; D003300:Copper; D014025:Titanium