Comparative study of spin dynamics in polybithiophene and poly(3-methylthiophene)

Abstract

Proton spin lattice relaxation time measurements have been carried out in the frequency range 6–100 MHz in ClO 4 − doped poly(3-methylthiophene) and polybithiophene powder samples. While exponential magnetization recovery is observed in poly(3-methylthiophene), the non-exponential relaxation which stands for polybithiophene is attributed to an heterogeneous distribution of electronic spins. An appropriate model allows one to extract T 1 values from the data. From their analysis it is concluded that electronic spin motion is dominated by a quasi 1-D diffusion in both materials with similar parameters. This result is then discussed with respect to other properties of the materials, and to other materials, as well as to other conducting polymers.