Nickel‐Decorated Silver Nanowires for Polymer‐Based Magnetoelectric Composite

International audiencePolymer-based magnetoelectric composites are processed with an intrinsic piezoelectric poly(vinylidenefluoride-co-trifluoroethylene) (P(VDF-TrFE)) matrix and high-aspect-ratio magnetic nickel–decorated silver nanowires. These core/ shell wires are obtained by the polyol reduction of Ni2+ ions on high-aspect-ratio silver nanowires. Scanning electron microscopy and transmission electron microscopy analyses show a homogeneous and well-crystallized nickel layer. Magnetic properties of the intrinsic particles and their composites are measured and show a strong enhancement of the coercive field compared to spherical Ni nanopowders. They also show the existence of strong magnetic anisotropy in the composites. The composites processed with a small amount of metallic particles (0.3 vol%) allow the maintaining of the P(VDF-TrFE) crystalline phase and the ability of a macroscopic polarization. The latter is conducted under a 80 MV m−1 field, leading to a significant d33 (3.2 pC N−1). Thus, the magnetoelectric properties are analyzed and an important coupling coefficient αME equal to 1.8 V m−1 Oe−1 is measured