SAOG '95 ABSTRACT   

Recent advances in XPS instrumentation have led not only to large increases in basic instrument sensitivity, but also have brought easy access to imaging and point analysis capabilities. In particular scanning lens systems are important in that they provide both high spatial resolution mapping and newer "microprobe" style analyses whilst maintaining facilities for familiar and well characterised spectroscopic methods. Instruments based on magnetic immersion lenses provide maximum solid angle for collection and transport of photoelectrons and so enable high speed analysis with minimal sample damage. Suitable variable apertures in such spectrometers give facilities for angle resolved studies, which further enhance surface sensitivity.
Application of these new capabilities to the analysis of polymeric and other insulating materials is only useful, however, if a stable, routine, and easy to use means of "charge neutralisation" is available. Only then is it possible to acquire reliable, repeatable XPS data from insulators irrespective of their physical form and sample mounting requirements. The AXIS series of instruments provide a secure, easy means of charge compensation which uses characteristic properties of the magnetic lens and which operates over a wide range of conditions. The system enables confident determination and use of small binding energy shifts in both spectroscopy and mapping.

Fig. 1: Coated microspheres - detailed peak fit	Fig.2: XPS map polythene-graphite

Practical examples of the analysis of surface modified materials (microspheres - Fig. 1), natural materials, and overalyers (including the production of thickness maps) will be discussed in detail, together with examples of XPS imaging with closely separated energy levels ( Fig. 2)

1. Drummond, I.W., "Imaging XPS: The Different Methods Explained", Microscopy and Analysis, March 1992, p. 29.
2. Ratner, B.D., "Surface Characterisation of Polymeric Biomaterials", Polymer Preprints, Volume 24, No 2, p 50 ff. (August 1993).

This is, as you should know by now, an Acolyte site design