Alternating-current conductivity and dielectric permittivity of polyaniline doped with β-naphthalene sulphonic acid

Abstract

The alternating-current (ac) conductivity σ(ω) and the dielectric permittivity of polyaniline doped with β-naphthalene sulphonic acid (NSA) have been extensively studied in the temperature range of 300 K to 80 K and in the frequency range of 500 Hz to 10 MHz. The ac conductivity follows a power law in frequency, σ(ω)∝ωs, at high frequency, where s (≃0.85-0.88) is nearly independent of temperature. At low temperature the ac conductivity spectra show saturations for frequencies of the order of 106 Hz. The ac conductivity exhibits a scaling behaviour in the form σ(ω)/σ0 = 1 + (ω/ω0)n with 0.8