Electrical properties of polyaniline doped with metal ions

Electrical transport properties of undoped polyaniline (Pani) and Pani doped with Fe, Ni and La ions (named Pani-Fe, Pani-Ni and Pani-La) have been investigated using dc and ac conductivity data. It is shown that the Pani-Fe sample follows 3D variable range hopping (VRH) conduction while the Pani, Pani-Ni and Pani-La samples follow 1D VRH conduction. These results are discussed by comparing with conventional HCl-doped Pani. Ac conductivity studies carried out in the frequency range 42 Hz-5 MHz reveal the influence of dopants on inter-chain interactions. The dielectric response exhibits two well resolved relaxation processes, which appear to indicate phase segregation of doped and undoped regions in the samples.