Electronic excitations and radiation damage in polymers

Electron energy loss spectroscopy is an attractive technique for measuring the spectrum of electronic excitations in polymers. Spectra can be recorded over the entire energy range of valence and core electronic excitations from 1 to 400 eV with a resolution of 0.1 eV. The experiments reported here measured energy loss spectra of an 80 keV electron beam with an intensity of 6.5 × 10
⁻⁷
amp/cm
²
transmitted through thin films (−1000 Å) of polystyrene (PS), poly (2-vinylpyridine) (PVP), polyethylene (PE) and polymethylmethacrylate (PMMA), prepared by standard solvent casting techniques. The special purpose high resolution energy loss spectrometer, similar in design to a new 300 keV instrument,
¹
is capable of obtaining spectra before significant radiation damage effects are observed.