SPIN SUSCEPTIBILITY IN POLYANILINE - TEMPERATURE AND DOPING DEPENDENCE

Using a special electrochemical cell compatible with an ESR variable t emperature insert, the temperature dependence of the spin susceptibili ty of polyaniline films has been measured for different doping levels. It is shown that in the conducting Emeraldine Salt the spin susceptib ility decreases, with in particular zero Pauli susceptibilty. The data of the spin susceptibility versus doping are compatible with a polaro n / bipolaron equilibrium, with a polaron concentration being essentia lly temperature independent.