Dose dependence of visible range diffuse reflectivity for Si+ and C+ ion implanted polymers

Detailed insight into the near-surface area of the ion beam modified polymer is supplied by the measured diffuse reflectivity spectra. The near-surface layer (50÷150 nm) of bulk polymer samples have been implanted with silicon (Si+) and carbon (C+) ions at low energies (E=30 keV) and a wide range of ion doses (D=5.1012-2.1017 cm-2). The polymer materials studied were: ultra-high-molecular-weight polyethylene (UHMWPE), poly-propylene (PP), and poly-tetra-fluor-ethylene (PTFE). The diffuse optical reflectivity spectra Rd = f(λ) of the implanted samples have been measured in the visible range (λ=400÷830 nm). In this paper the dose dependences of the size and sign of the diffuse reflectivity changes ΔRd=f(D) have been analyzed.