Magnetoelectric Coupling Effect in Ferroelectric and Ferromagnetic Hybrid Thin Films

Abstract

Magnetoelectric (ME) effect in multiferroic or ferroelectric/ferromagnetic composite thin films occurs through the elastic coupling between the piezoelectric properties of ferroelectric and magnetostrictive properties of ferromagnetic component. To obtain high elastic coupling and ME effect, we introduced PZT [Pb(Zr_0.52, Ti_0.48)O₃] as a ferroelectric materials and CuFO (CuFe₂O₄) as ferromagnetic materials because of their high piezoelectric coefficient and magnetostrictive properties among various metal-oxide materials. To evaluate ME effect, we prepared CuFO/Pt/PZT/Pt hybrid thin films directly on Pt/TiO₂/SiO₂/Si substrate by using ion beam sputtering and spin-coating method. We investigated the microstructures and morphologies of hybrid thin films by XRD and SEM, the ferroelectric and ferromagnetic behaviors of hybrid films were examined by measuring polarization and magnetization hysteresis loops vs. electric and magnetic field. Magnetoelectric coefficients were calculated by measured magnetoelectric voltages using magnetoelectric measurement system. In this research, we’ll discuss the relations between annealing temperatures and multiferroic properties.