Conduction and dielectric relaxation studies on substituted iron(II) phthalocyanine thin film

The dc conductivity and complex impedance behavior of spin-coated 2,9,16,23-Tetra(chloro)-3,10,17,24-tetra(4-(4-methoxyphenyl)- 8 methylcoumarin-7-yloxy)phthalocyaninatoiron-(II) (7) thin film was investigated over a temperature range of 298–550 K. The results obtained on dc conductivity reveals that the conduction is dominated by the variable range hopping in three dimension. Analysis of the frequency dependent conductivity data shows that the variation of the frequency exponent (n) is consistent with the predictions of the correlated barrier hopping (CBH) model below 425 K. On the other hand, the temperature dependence of n becomes stronger than model predictions above 425 K. Complex dielectric formalism was used in order to investigate the dielectric relaxation mechanism in the film. Non-Debye type relaxation process was observed. It was found that the imaginary part of the dielectric function varies as Bω^s with s in the range of 0.35–0.68.