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

The temperature dependences of the conductivity σ(T) and magnetoconductivity (MC) of poly(3,4-ethylenedioxythiophene), PEDOT, doped with PF6 BE4, and CF3SO3 have been studied down to 1.2 K. The transition in σ(T) from negative to positive temperature coefficient of resistivity, TCR, has been found below 10 K for samples with ρr = ρ(1.4 K)/ρ(291 K) ≈ 1.5–2.8. For negative and positive TCR, the σ(T) is isotropic and ~ T1/2. The MC is negative, isotropic and ~ H2 and H1/2 at low and high magnetic field respectively. The results are explained as resulting of the dominant influence of electron-electron interactions on the σ(T).