文摘
Magnetic susceptibility measurements on conducting polyaniline and polypyrrole nanostructures with differentdopant type and doping level as functions of temperature and magnetic field are reported. The susceptibilitydata cannot be simply described as Curie-like susceptibility at lower temperatures and temperature-independentPauli-like susceptibility at higher temperatures; some unusual transitions are observed in the temperaturedependence of susceptibility, for example, paramagnetic susceptibility decreases gradually with loweringtemperature, which suggests the coexistence of polarons and spinless bipolarons and possible formation ofbipolarons with changing temperature or doping level. In particular, it is found that the direct current magneticsusceptibilities are strongly dependent on applied magnetic field, dopant type, and doping level.