• Corrosion Science and Technology
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• v.6 no.4
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• pp.198-205
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• 2007

The initial stages of electrochemical oxidative CuI film formation on Cu(111), as studied by means of Cyclic Voltammetry (CV), in-situ Scanning Tunneling Microscopy (STM) and ex-situ Synchrotron X-ray Photoemission Spectroscopy (SXPS), indicate a significant acceleration of copper oxidation in the presence of iodide anions in the electrolyte. A surface confined supersaturation with mobile CuI monomers first leads to the formation of a 2D-CuI film via nucleation and growth of a Cu/I-bilayer on-top of a pre-adsorbed iodide monolayer. Structurally, this 2D-CuI film is closely related to the (111) plane of crystalline CuI (zinc blende type). Interestingly, this film causes no significant passivation of the copper surface. In an advanced stage of copper dissolution a transition from the 2D- to a 3D-CuI growth mode can be observed.

• Journal of the Korean Vacuum Society
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• v.13 no.2
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• pp.86-91
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• 2004

Transiton-metal gallides attract wide interest as a candidate for high-temperature structural materials. In a wide composition range, in which it was known that Co-Ga alloy have CsCl (B2) crystallographic structure, a systematic study on the correlation between physical properties and electronic structures of Co-gallides was performed. $Co_{l-x}Ga$ $_{x}$ alloys ($0.35\leq$x$\leq0.55$) were prepared by arc-melting method and were annealed at $1000 ^{\circ}C$ for 48hour to increase the homogeneity. In this composition range all the prepared alloys have the CsCl (B2) structure. The chemical states and the electronic structure were studied by using x-ray photoemission spectroscopy (XPS), and x-ray absorption near-edge structure (XANES), and exhibit different physical properties depending on the composition. During the annealing, a significant oxidation has happened and all the oxygen atoms are incorporated with the Ga atoms to form a $Ga_2O_3$ phase. In a view point of electronic structure, the $Co_{l-x}Ga$ $_{x}$ alloys were formed by the Ga(p) - Co(d) hybridization.