DOPING OF ION-IRRADIATED POLYETHYLENTEREPHTALATE FROM WATER SOLUTION OF LICL

Polyethylenterephtalate foils (10 mu m thick with the density of rho=1 .3 g cm(-3)) were irradiated with 150 keV Ar+ ions to fluences from 5x 10(11) to 1x10(15) cm(-2) and one gear after the irradiation they were exposed to a 5 M water solution of LiCl at the boiling point for time s ranging from 15 s up to 8 h. The depth profiles of incorporated Li a toms as a function of the ion fluence and the doping time were determi ned using the neutron depth profiling technique based on the Li-6(n(th ), alpha)H-3 nuclear reaction. The Li content in the 600 nm thick surf ace layer achieves saturation very rapidly, already after 15 s doping time, and it exhibits a local, pronounced maximum at 2 or 4 h doping t imes for the specimens irradiated to fluences below and above 5x10(14) cm(-2), respectively. The concentration depth profiles of incorporate d Li atoms consist of a pronounced surface component, obviously connec ted with radiation damages created by the ion irradiation and a long i nward tail which is due to regular diffusion in pristine polymer. As a function of ion fluence, the Li content increases up to the fluence o f 5x10(13) cm(-2) and then declines in most cases. The surface compone nt of the Li depth profiles changes dramatically with increasing ion f luence from bell-shaped ones for fluences below 5x10(14) cm(-2) to tho se characterized by a depleted surface layer and a rather sharp concen tration maximum at depths significantly exceeding the calculated ion p rojected range.