Giant Piezoelectricity Driven Magnetoelectric Coupling in a Multiferroic Membrane Heterostructure*

Strain intermediated magnetoelectric coupling in thin film heterostructures is a promising paradigm for sensors and information storage devices, but it is hindered by substrate clamping. We prepared a freestanding, unclamped, 500 nm thick, (001) oriented [Pb(Mg_1/3Nb_2/3)O₃]_0.7-[PbTiO₃]_0.3 (PMN-PT) membrane with a 35nm ferromagnetic Ni overlayer. Magneto-optic Kerr magnetometry shows that upon applying a bias voltage, an in-plane magnetic anisotropy of 5 kJ/m³ forms, resulting in Ni magnetization rotation. Additionally, the large strains in these devices cause macroscopic bending and flexing, which was characterized with laser Doppler vibrometry and white light interferometry.