Electron kinetic energy through mean free path

Figure 3. Electron mean free path as a function of electron kinetic energy through organic materials. Key V, PMMA , poly(p-xylene) O, plasma polymerized fluorocarbon , barium stearate 0, cadmium arachidate and A, carbon. (Reproduced, with permission from Ref. 35.)...

A technique becomes surface sensitive if the radiation or particles to be detected travel no more than a few atomic distances through the solid. Figure 3.1 shows that the mean free path, A, of electrons in elemental solids depends on the kinetic energy, but is limited to less than 1-2 nm for kinetic energies in the range 15-1000 eV [16]. 

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