ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Polyethylene samples implanted with 150 keV F+ ions to the doses 1011-1015 cm-2 were doped with iodine by exposing them to iodine vapors at 90°C for 3 h. The iodine depth profiles, measured by Rutherford back-scattering techniques, evolve dramatically with increasing implanted doses, from “bumpy” profiles at lower fluences to a “depleted” one comprising two concentration maxima with no iodine in between observed at highest dose. The areal density of iodine incorporated into the 500-nm-thick surface layer is proportional to the ion dose for the doses ≤ 1 × 1013 cm-2 and it achieves a saturation or declines at higher doses. The results support the concept of enhanced iodine diffusion in the radiation-damaged surface layer and its trapping on the radiation defects within. The sheet resistivity of as-implanted PE is practically constant, independent of the implanted dose. Iodine doping of the ion-implanted PE samples results in immediate, strong decrese of the sheet resistivity by 3-4 orders of magnitude which, however, is not stable. The measured temperature dependence of the sheet resistance indicates p-semiconducting character of ion-implanted and iodinated samples at the temperatures below the PE melting point. The iodine redistribution and/or escape with increasing temperature is observed. © 1996 John Wiley & Sons, Inc.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
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