Ag/Cu(100) Surface Alloy and Polycrystalline Cu(Ag) Alloy Studied by XPS

In this work, polycrystalline Cu(Ag) bulk alloy (1 wt.% Ag) and Ag/Cu(100) surface alloy (0.9 ML Ag) have been characterized by x-ray photoelectron spectroscopy (XPS) employing Al K α and Mg K α radiation. XPS spectra of the principal core levels (Cu, Ag) are presented together with XAES (x-ray induced Auger electron spectroscopy) spectra of the Cu LMM transition. The samples were prepared in situ by argon ion sputtering at room temperature and subsequent annealing at 700 K. Ag overlayer was deposited on the Cu(100) surface by a resistively heated Ag evaporator. The absence of contaminants such as C or O was confirmed by XPS. Together, the industrial Cu(Ag) alloy and the well defined Ag/Cu(100) model system serve as a template for studies of nanoscale surface oxidation and segregation phenomena.