DAMAGE PROFILE EXAMINATION ON ION-IRRADIATED PEEK BY LI-6 DOPING AND NEUTRON DEPTH PROFILING TECHNIQUE

Depth structure of radiation damaged surface layer of poly(aryl-ether- ether ketone) (PEEK) a polymer was studied using doping with Li-6 atom s combined with nondestructive neutron depth profiling (NDP) method. T he PEEK foils were irradiated with 2 MeV O+ ions up to a fluence of 6 x 10(14) ions/cm(2). The damage profiles in the samples were visualize d by doping of the samples with 5 M LiCl water solution at room temper ature (RT) for 22.5 h. The Li ions are trapped on ion-produced radiati on defects and the Li depth profiles are determined by the NDP method. NDP experiments were performed before and after leaching of excess of lithium atoms from the samples in distilled water at RT for 2 h. The leaching leads to dramatic changes in the Li depth distribution which, at low ion fluences, is similar in shape to the electronic energy los s profile of 2 MeV O+ ions. For the higher fluences double-peaked prof ile occurs, which indicates a competition between different degradatio n processes in ion irradiated polymer. (C) 1998 Elsevier Science B.V. All rights reserved.