Polyethylene (PE) foils, 15 mu m thick, were irradiated with 150 keV Ar+ io
ns to the fluences from 1x10(12)-1x10(15) cm(-2) and subsequently doped wit
h iodine from gaseous and liquid phases. The modified PE was examined using
several analytical techniques with the aim to determine the mechanism of i
odine doping of radiation damaged PE. Following techniques were used for th
is purpose: Rutherford back-scattering (depth profiles of elements in near
surface layer), Cahn-electrobalance (total amount of incorporated iodine),
sheet resistance measurement by two-point technique, electron paramagnetic
resonance (free radical concentration), X-ray diffraction (identification o
f crystalline phase in PE), FTIR and Raman spectroscopy (chemical and struc
tural changes, complex detection). A part of iodine atoms introduced from v
apours as I-2(0) is bound to the sites on the PE macromolecular chain damag
ed by ion impact and it does not affect the sheet resistivity. Other iodine
atoms, which act as electron accepters, form polyiodine ions enhancing ele
ctrical conductivity. This conclusion is supported by the results obtained
on PE doped with polyions from water solution, where no significant change
of the electrical conductivity was observed. (C) 1999 Elsevier Science B.V.
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