Influence of the stress on magnetoelectric effect in magnetostrictive-PZT bilayers

Abstract

In this letter, we investigate the influence of the stress on magnetoelectric (ME) effect in a magnetostrictive-PZT bilayer. ME voltage coefficient α^*E =δEδH?????, where δE is the induced electric field for an applied alternating current (ac) magnetic field δH, is obtained by solving the stress-related piezoelectric constitutive equation and the conventional magnetostrictive equation with appropriate boundary condition. Based on the free-energy density function of the PZT film in stress state, we get the stress-related piezoelectric charge coefficient ^pd^*₃₁ and dielectric permittivity ^pε^*₃₃. After taking the cobalt ferrite (CFO) as magnetostrictive phase, it is found that α^*E increases with decreasing 2-d compressive stress for CFO-PZT, which not only is qualitatively consistent with previous experimental measurements, but also provides a possible route to improve the ME effect.