Project 193 was concerned with the development for XPS of a traceable energy scale and a procedure for the determination of spectrometer energy-intensity response functions relative to that of a spectrometer of a specific design. Having achieved these it is now possible to compare results from different instruments provided that they are operated under standard conditions. To enable true quantification to be achieved and for comparison of results made under practical operating condition, it is necessary to produce a small number of reference materials which will provide peaks of known intensity throughout the spectrum. This may be achieved by utilizing the well defined stoichiometry of fuzed quartz and the ability to graft onto the surface exact monolayers of stable organic compounds containing fluorine. By employing both planar and granular materials the effects of surface roughness also become quantifiable.
Fuzed quartz either in its as cleaned state or with a hydrolyzed surface was shown to not to be sufficiently stable for use as a surface analysis reference material without the need for ion etch cleaning.
Similarly when surface layers of either alkylsilanes, perfluorinated silanes or chlorosilanes were grafted onto SiO2 layers their stability in the atmosphere or under X-ray irradiation was not high enough to enable them to be used as reference materials for either XPS or SIMS.
By contrast when the polymers were grafted onto a chromium surface they were found to be much more stable.