Ac conductivity and dielectric properties of bulk tin phthalocyanine dichloride (SnPcCl<inf>2</inf>)

Abstract

The ac conductivity, σac(ω), has been measured for bulk tin phthalocyanine dichloride (SnPcCl2) in the form of compressed pellet with evaporated ohmic Au electrodes in a temperature range 303-403 K. Ac conductivity, σac(ω), is found to vary as ωs in the frequency range 42 Hz-5×106 Hz. At low range of frequency, s<1 and it decreases with the increase in temperature indicating a dominant hopping process. At high range of frequency, s is found to be equal to ≈1.09 and is temperature independent. The dielectric constant, ε1, and dialectic loss, ε2, have been determined for bulk SnPcCl2. Both ε1 and ε2 decrease with the increase in frequency and increase with the increase in temperature. The Cole-Cole types have been used to determine some parameters such as; the macroscopic relaxation time (τo), the molecular relaxation time (τ), the activation energy for relaxation (Eo) and the distribution parameter (α). The temperature dependence of τ is expressed by a thermally activated process with the activation energy of 0.299 eV. © 2008 Elsevier B.V. All rights reserved.