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This is an extremely sensitive surface technique in which a narrow beam of low energy electrons is aimed at the surface of the material under investigation. The beam strikes the surface, and reflected electrons can be "focussed" and used to form an image. At very low energies it may be referred to as Mirror Electron Microscopy (MEM).
Images can be captured rapidly, and this means it is possible to see changes over a period of time - effectively to make a "movie" of surface changes taking place.
Work with this technique at the Fritz Haber Institute in Berlin has allowed the oxidation of carbon monoxide to carbon dioxide on the surface of a platinum catalyst to be studied in detail. This is one of the key reactions that occur in a catalytic converter.

 

 

 

 

 

 


 

 

 

 

 

 

 

 

X-Ray and High Energy UV Spectroscopy

Both X-rays and high energy UV have sufficient energy to eject electrons from the surface atoms. The energy of the emitted electrons can be analysed to give information about the atoms and molecules at the surface from which the electrons have originated.

 

 

 

 


 

 

 

 

Low Energy Electron Microscopy
Infra Red Spectroscopy

IR absorption spectroscopy is commonly used to identify materials, as different substances have different IR "fingerprints" (see spectra for hdpe and ldpe). This can be adapted to aid the study of the surface of a material. The intensity of the incident infra-red beam is compared with the intensity of the infra-red beam reflected from the surface, giving an infra-red absorption spectrum of the material bonded to surface atoms.