Self-assembled core-shell CoFe2O4@BaTiO3 particles loaded P(VDF-HFP) flexible films with excellent magneto-electric effects

Flexible composited multiferroic films with excellent magnetic-electric effects were prepared. The films were composed of self-assembled CoFe2O4@BaTiO3 core-shell nanoparticle fillers and a poly(vinylidene fluoride-co-hexafluoropropene) matrix. The CoFe2O4@BaTiO3 core-shell particles were prepared using a hydrolysis-hydrothermal method. The surface modification of CoFe2O4 with the cationic surfactant cetyltrimethyl ammonium bromide promoted the BaTiO3 nanocrystals' self-assembly precipitation. Compared with the films loaded by bare CoFe2O4, the films filled with core-shell particles exhibited reduced leakage current density, enhanced dielectric properties, ferroelectric (FE) polarization, and magneto-electric (ME) effects. An excellent ME voltage coefficient of 1835 mV/cm Oe was measured at a DC bias field of −3500 Oe and an AC magnetic field of 3.5 Oe with a frequency of 45 kHz. This enhancement of ME effects was attributed to the large FE-ferromagnetic (FM) interface to volume and the increment of induc...