Magnetoelectric properties of nickel nanowires-P(VDF–TrFE) composites

• A magnetic anisotropy of the ferromagnetic Ni nanowires was observed.
• The P(VDF–TrFE) glass transition has an influence on the NWs Ni/P(VDF–TrFE) 0.3% vol composite magnetic properties.
• The NWs Ni/P(VDF–TrFE) composite was polarized to obtain a significant piezoelectric coefficient of 7 pC N−1.
• The magnetoelectric coefficient reached the high value of 237 V/(m Oe).

Multiferroic composites with very high magnetoelectric coupling composites have been elaborated by incorporating high aspect ratio magnetic nickel particles in a ferroelectric matrix P(VDF–TrFE). Nickel nanowires (NWs) were elaborated by the electrodeposition method which allows obtaining a constant aspect ratio of 250. SEM-FEG images showed a Ni NWs homogeneous dispersion in acetone or in the P(VDF–TrFE). HR-TEM images and electronic diffraction studies revealed that the Ni NWs are monocrystalline, thanks to the electrodeposition method. Magnetic measurements showed a strong anisotropy of the magnetic particles, the coercivity is higher in the parallel direction (160 Oe). This anisotropy decreased for the composites due to the diminution of the Ni NWs interactions. The piezoelectric coefficient obtained after the composite polarization was significant (7 pC N−1) under a polarization field of 60 kV mm−1. The magnetoelectric coefficient reached the value of 237 V/(m Oe) at 4 kHz. According to the previous studies, this value is the highest one found for multiferroic polymer matrix composites.