| NUKLEONIKA 1997, 42(1):253-259
DOPPLER-BROADENING STUDIES OF SURFACE-MODIFIED CONDUCTING POLYETHYLENEG. Wisniewski1, G. P. Karwasz2, R. S. Brusa2, A. Zecca2 1 Gdansk Technical University, Faculty of Technical Physics, 80-952 Gdansk, Poland 2 Universita di Trento, Dipartimento di Fisica, 38050 Povo (TN), Italy Carbon doped, conducting polyethylene has been studied by positron annihilation techniques: bulk lifetime and depth-resolved Doppler broadening analysis. Lowering of the Doppler broadening S-parameter as been observed for samples just at the percolation theresold. Chemical modifications reduce diffusion of positrons in near surface layers. Doping with carbon does not change free-volumes, as monitored via long component of the positron lifetime spectrum. Close X |