Ferrocene derivatives and aniline copolymers with tunable magnetoresistance and dielectric properties

Inspired by the electron-rich characteristics of ferrocene (Fc), we have strategically integrated this compound into polyaniline (PANI), aiming to modulate the magnetoresistance (MR) and dielectric properties of PANI. The copolymers (P(ANI-co-FcA)) are synthesized by copolymerization of aniline and 1,1'-bis[[(4-aminophenyl)amino]carbon]ferrocene (FcA). The resistivity and temperature-dependent resistivity are measured to unveil the charge carrier transport mechanism, aligning with the Efros-Shklovskii variable-range hopping (ES-VRH) model. Additionally, the MR and dielectric properties are tuned by alternating the FcA content in the main chain of copolymers. MR analysis reveals a positive effect, which is intensified with an increased FcA content. Notably, the MR effect of P(ANI-co-FcA)-3 containing 31.92 wt% FcA attains 1.51% under a magnetic field of 3 T. The real permittivity of copolymers is changed from negative to positive values upon the incorporation of FcA. This research proffers an approach to manipulate the electrical performance of conducting polymer materials for potential applications in electronic devices.