Bending Modes and Magnetoelectric Effects in Asymmetric Ferromagnetic-Ferroelectric Structure

摘要

A model is discussed here for the resonance enhancement of magnetoelectric (ME) interactions in ferrite-piezoelectric bilayers at frequencies corresponding to bending oscillations. The thickness dependence of stress, strain and magnetic and electric fields within the sample are taken into account so that the bending deformations could be considered in an applied magnetic or electric field. The boundary conditions corresponding to bilayers that are free to vibrate at both ends, or simply supported at both ends, or fixed at one end are considered. The explicit expressions for ME voltage coefficients are derived by way of exact solution of electrostatic, magnetostatic and elasto-dynamic equations for thin plate and disk-shaped bilayers. The model is applied to a specific case of nickel and lead zinconate titanate (PZT) bilayer. Theoretical ME voltage coefficients versus frequency and PZT to nickel thickness ratio profiles are in excellent agreement with data.