A monolayer interface of plasma-polymerized polystyrene on niobium: an in situ electron spectroscopy study

Abstract Photoelectron spectroscopy utilizing X-ray (XPS) and ultraviolet (UPS) radiation has been used to study the electronic structure of the polystyrene/niobium interface. Polystyrene layers have been deposited in situ by anodic DC plasma polymerization (DCPP) on the niobium substrate. A surprisingly thin NbC phase, with monolayer thickness, is found to be formed at the polymer/metal interface. The good adhesion properties of the polystyrene film on the Nb substrate are correlated with the formation of the NbC phase. Moreover it is found that the formation of a NbC interface would also result from a simple exposure of the Nb substrate to styrene vapour.