Magnetoelectric effect of lead-free perovskite BiFeO3/Bi0.5(Na0.85K0.15)0.5TiO3 composite films

Lead-free BiFeO3/Bi-0.5(Na0.85K0.15)(0.5)TiO3 bilayer composite films were prepared using chemical solution deposition. The microstructure, ferroelectric and leakage properties, domain structure, dielectric properties, piezoelectric properties, magnetic properties as well as magnetoelectric effect were investigated for the composite films. Well-defined interfaces between BiFeO3 and Bi-0.5(Na0.85K0.15)(0.5)TiO3 layers and clear domain structures were observed. The composite films not only exhibit ferromagnetic and ferroelectric properties, but also possess strong magnetoelectric effect at room temperature. Thus outstanding magnetoelectric properties are attributed to similar bismuth system single-layer perovskite structure and the excellent coupling effect between BiFeO3 and Bi-0.5(Na0.85K0.15)(0.5)TiO3 layers, which obtains a strong coupling interaction between ferromagnetic and ferroelectric phases. The present work provides a simple way to fabricate lead-free composite films with strong magnetoelectric effect, and facilitating their applications in micro-electro-mechanical systems and information storage devices. (C) 2016 Elsevier B.V. All rights reserved.