Magnetoelectric effect in a flexible heterostructure comprising magnetostrictive fiber composite and piezopolymer PVDF

Abstract

Linear and nonlinear magnetoelectric (ME) effects in flexible composite heterostructures comprising layers of magnetostrictive fiber composite (MFC) and poly(vinylidene fluoride) (PVDF) piezopolymer have been observed and investigated. MFC consists of a set of Ni-wires with a diameter of 100, 150, or 200 μm arranged in parallel close to each other in one layer and placed in a polymer matrix. The structure was excited by an ac magnetic field in the frequency range of 1-15 kHz and simultaneously magnetized in the plane by a dc field H. The voltage generated by the PVDF layer was recorded at the frequency of the structure bending resonance. The ME coefficient of 5.8 V/(Oe cm) was obtained for a heterostructure with Ni-wires 150 μm in diameter at a frequency of 5.1 kHz when magnetized along the wires. The ME effect magnitude depends on the H-field orientation relative to the Ni-wires due to the magnetostriction anisotropy arising from demagnetization effects. The generation of ME voltage second harmonic with an efficiency of 26 mV/(Oe2·cm) was observed in the heterostructure with an increase in the excitation field.