Vibrational spectra of silicon implanted polymethyl-methacrylate (PMMA) and poly-propylene (PP)

Infra-red (IR) and Raman spectroscopy studies were used to characterize different polymer materials implanted with low energy Si⁺ ions (E = 30 keV, D = 1.10¹⁷ cm^-2). Two kinds of polymer were studied - poly-methyl-methacrylate (PMMA), and poly-propylene (PP). Silicon ion implantation resulted in the breaking down of bonds in the substrate structures, and the emergence of newly formed bonds. The IR and Raman studies thus show that the implantation of Si⁺ into PMMA and PP leads to the formation of amorphous and nano-crystalline graphite, predominantly in the PP samples. The presence of SiC particles and unreacted Si atoms is also observed in the implanted polymer material.