Beam damage

Figure Al.7.13. ESDIAD patterns showing the angular distributions of F emitted from PF adsorbed on Ru (0001) under electron bombardment, (a) 0.25 ML coverage, (b) the same surface following electron beam damage.

Madey T E ef a/1993 Structure and kinetics of electron beam damage in a chemisorbed monolayer PFjOn Ru(OOOI) Desorption Induced by Electronic Transitions DIET V vol 31, ed A R Burns, E B Stechel and D R Jennison (Berlin Springer)... 

All elements, but not element specific No, except in special cases of electron-beam damage 4-20 A... 

Not usually, sometimes from available core levels No, some beam damage to radiation-sensitive material... 

AES is a useful element-specific technique for quantitative determination of the elemental composition of a surface. Although some chemical information is available in principle, the technique is used largely for elemental analysis. Electron beam damage can decompose organic adsorbates and cause damage, particularly on insulating surfaces. In some cases, the beam can reduce metal oxides. 

Fig. 5. HRTEM image of MAPO-36 showing well-defined large apertures. The inset shows the computed image where the outline of the 12-rings is clearly visible (top and bottom are with and without taking beam damage into account) (5,43).

In fig. 6a.b we can observe as examples how the user can define different areas of the ED pattern (lines, or regions around spots ) can select in order to speed up time of measurement and avoid unnecessary beam damage, or concentrate the study in selected group of reflections ( e.g symmetry-related reflections or superstructure reflections). 

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