Induced Magnetoelectric Effect Driven by Magnetization in BaFe12O19- P(VDF-TrFE) Composites

Films of BaFe₁₂O₁₉/poly(vinylidenefluoride)-trifluorethylene composites with 5, 10, and 20 wt% barium ferrite content have been fabricated. BaFe₁₂O₁₉ microparticles have the shape of thin hexagonal platelets, the easy direction of magnetization remaining along the c-axis, which is perpendicular to the plates. This fact allows for ferrite particles orientation in-plane and out-of-plane within the composite films, as confirmed by measured hysteresis loops. While the in-plane-induced magnetoelectric (ME) effect is practically zero, these composite films show a good out-of-plane ME with maximum ME coupling coefficient changes of 3, 17, and 2 mV/cm.Oe for the 5, 10, and 20 wt% barium ferrite content films, respectively. We conclude that this ME behavior appears to be driven by the magnetization process arising when we applied the external magnetic field. We have also measured the linear and reversible ME effect for low applied bias field, when magnetization process is still reversible.