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Abstract

With a new cell design, simultaneous electrochemical ESR and conductance measurements were realized for the first time. The in_situ cell consisted of a dual working electrode, a counter electrode and a reference electrode accommodated in a capillary of 1mm diameter. The dual working electrode was composed of two closely spaced Pt electrodes: a Pt disk electrode(0.5 mm diameter)sealed in a thin glass tube and a Pt layer deposited on the outside wall of the glass tube.The two working electrodes were separated by the glass gap about 20 μm thick. Two potentiostats were used to control electrode potential and maintain 10 mV potential difference between the two working electrodes. The conductivity of the polyaniline was deduced from the current passing through the polymer across the glass gap. With the new technique, an unprecedented detailed picture was obtained revealing the potential dependences of conductivity and ESR behaviors, including ESR intensity, lineshape, and saturation. Experimental results showed that the conduction mechanism could be well interpreted within the framework of the polaron lattice model. The ESR saturation data also provided a new experimental evidence for the transformation between Curie spins and Pauli spins.

Publication Date

2000-02-28

Online Available Date

2000-02-28

Revised Date

2000-02-28

Received Date

2000-02-28

References

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