Metallic conductivity of highly doped poly(3,4-ethylenedioxythiophene)

The temperature dependences of the conductivity sigma(T) and magnetoconduct ivity (MC) of poly(3,4-ethylenedioxythiophene), PEDOT, doped with PF6, BF4, and CF3SO3 have been studied down to 1.2 K. The transition in sigma(T) fro m negative to positive temperature coefficient of resistivity, TCR, has bee n found below 10 K for samples with rho(r) = rho(1.4 K)/rho(291 K) approxim ate to 1.5-2.8. For negative and positive TCR the cr(T) is isotropic and si milar to T-1/2. The MC is negative, isotropic and similar to H-2 and H-1/2 at row and high magnetic field respectively. The results are explained as r esulting of the dominant influence of electron-electron interactions on the sigma(T).