CARBONACEOUS CLUSTERS IN IRRADIATED POLYMERS AS REVEALED BY UV-VIS SPECTROMETRY

Carbonaceous clusters-supposed to be the carriers of electric conductivity-are formed along latent tracks of energetic ions in polymers. The different experimental techniques for cluster determination are summarized. Here we present some new results which have been derived from UV-Vis spectrometric examinations. Especially the initial phase of cluster growth is studied in derail. There are hints that a threshold energy density has to be deposited in the polymer before cluster growth sets in. This threshold is similar to the one for producing radicals (as seen by EPR studies), and to the one for the onset of strong polymeric conductivity. The cluster growth is shown to scale rather well with the mean transferred electronic energy density. The increase in cluster growth with energy density is much slower than the one of radical formation and conductivity.