Piezoelectric control of the magnetic anisotropy via interface strain coupling in a composite multiferroic structure

¹ Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University Lanzhou 730000, China
² Institut für Physik, Martin-Luther Universität Halle-Wittenberg - 06099 Halle (Saale), Germany, EU
³ Centro de Investigación en Materiales Avanzados (CIMAV S.C.) - Chihuahua/Monterrey, 31109 Chihuahua, Mexico

^(a) Cheng-long.Jia@physik.uni-halle.de
^(b) Jamal.Berakdar@physik.uni-halle.de

Received: 2 May 2012
Accepted: 5 June 2012

Abstract

We investigate theoretically the magnetic dynamics in a ferroelectric/ferromagnetic heterostructure mediated by a strain-induced magnetoelectric interaction. The epitaxial strain involves a strong piezoelectricity and interfacial magnetoelastic coupling, the interplay of both gives rise to an electrically tunable uniaxial magnetic anisotropy. We predict an electric-field–induced magnetic switching in the plane perpendicular to the magneto-crystalline easy axis while the total magnetization remains stable. We trace this effect back to the ferroelectric control of the magnetic anisotropy. We also inspect the magnetic remanence and the electric coercivity and demonstrate a pronounced dynamic magnetic response to an electric field in a thin ferromagnetic layer.