Ion beam induced carbonization of partially cured phenolic resin

Partially cured phenolic resin films were irradiated with N5+ ions at 6.5 MeV, He2+ ions at 1.5 MeV and protons at 0.5 MeV. These films were prepared by spin coating and subsequent annealing at 150 C. Irradiated volumes in each sample were tested in situ for enhanced electrical conductivity and later on by Raman microprobe spectroscopy. Raman microprobe spectroscopy of the darkened phase shows development of the D and G lines which are characteristic of the production of a carbonized resin. This localized transformation, depending on the energy and type of the incident ion, occurred preferentially at a shallow depth rather than throughout the volume and is due to the direct energy transfer from beam to target, localized thermal annealing processes and the chemical reaction between stopped neutralized incident ion and the sample depending on the type of the species used for bombardment. ((orig.))