Surface analysis of some polymer-based materials by means of a soft X-ray emission technique

This paper reviews the performances and limits of low-energy electron-induc ed X-ray spectroscopy (LEEIXS) in the surface and thin film analysis of pol ymer-based materials. The major interest of this soft X-ray emission techni que results from the use of a windowless gas discharge tube operating in th e primary vacuum of the X-ray spectrometer as an electron excitation source (1-5 keV). The capabilities of LEEIXS are illustrated through the analysis of light elements (C, O, F, Si, etc.) (i) in thin polymeric films deposite d on metallic substrates from various wet (dipping, electrodeposition, elec tropolymerization) and dry (plasma polymerization, thermal evaporation) pro cesses and (ii) on polymer substrates subjected to chemical or physical sur face treatments. These examples also show that LEEIXS analysis, when it con cerns organic or polymeric materials, is limited to those materials which p resent a sufficient chemical and thermal stability, as the electron beam bo mbardment, in spite of the low current density (0.1 mA cm(-2)) used, can ca use degradation of many materials.