Study of the influence of structural hysteresis on polaron interactions of lightly doped poly(3-dodecylthiophene) with FeCl3

EPR, dc and ac magnetic measurements on lightly doped poly(3-dodecylthiophene) with FeCl3 are reported. The zero-field-cooled and field-cooled curves obtained by a SQUID magnetometer confirmed magnetic hysteresis, beginning close to the room temperature. Magnetic hysteresis is close-knit with structural irreversibility of polymeric chains. Structural irreversibility induces changes in proportions of diamagnetic, Pauli, Currie, and polaron magnetic contributions of the polymeric system.