Study of 160 MeV Ni12+ ion irradiation effects on electrodeposited polypyrrole films

Conducting polymer polypyrrole thin films doped with LiCF3SO3, [CH3(CH2)(3)](4)NBF4 and [CH3(CH2)(3)](4)NPF6 have been electrodeposited potentiodynamically on ITO coated glass substrate. The polymer films are irradiated with 160 MeV Ni12+ ions at three different fluences of 5 x 10(10), 5 x 10(11) and 3 x 10(12) ions cm(-2). An increase in do conductivity of polypyrrole films from similar to 100 S/cm to similar to 170 S/cm after irradiation with highest fluence is observed in four-probe measurement. X-ray diffractogram shows increase in the crystallinity of the polypyrrole films upon SHI irradiation, which goes on increasing with the increase in fluence. Absorption intensity increase in the higher wavelength region is observed in the UV-Vis spectra. The SEM studies show that the cauliflower like flaky microstructure of the surface of polypyrrole films turns globular upon SHI irradiation at fluence 5 x 10(11) ions cm(-2) and becomes smooth and dense at the highest fluence used. The cyclic voltammetry studies exhibit that the redox properties of the polypyrrole films do not change much on SHI irradiation. (c) 2005 Elsevier B.V. All rights reserved.