Structure, dielectric, AC and DC conduction properties of acid doped polyaniline films

Capacitors with Al-pani (CH3SO3H)-Al sandwich film structure were fabricated. The top and bottom aluminium electrodes were deposited by vacuum evaporation and the pani (CH3SO3H) film deposited by a solution casting method. An X-ray diffractogram indicates the amorphous nature of the polymer films. The thicknesses of the films were measured by capacitance, weighing and Rutherford back scattering (RBS) methods. Annealing, dielectric and AC conduction properties were studied in the frequency range 10 kHz-10 MHz for various temperatures (303-423 K). DC conduction studies were made for these films in the temperature range 303-443 K. The capacitance of the film decreases with increasing frequency. AC conduction studies suggest that hopping of polarons are responsible for conduction. DC conduction studies reveal that the Poole-Frenkel type of conduction is predominant at high fields. (C) 1997 Elsevier Science Ltd.