Electric-field-control of magnetic remanence of NiFe2O4 thin film epitaxially grown on Pb(Mg1/3Nb2/3)O3–PbTiO3.

We propose an asymmetric bilayer structure in which the magnetic remanence (M_R) is controlled by the in-plane strain of the top NiFe₂O₄ (NFO) layer epitaxially constrained by the bottom Pb(Mg_1/3Nb_2/3)O₃-PbTiO₃ (PMN-PT) substrate. In this asymmetric structure, an electric-field-induced giant piezoelectric strain from the bottom PMN-PT layer is effectively transferred to the top NFO layer. We have shown that the room-temperature magnetic remanence (M_R) of the 100-nm-thick NFO layer is enhanced by 46% when an electric-field-induced in-plane compressive strain is about -0.1%. Synchrotron x-ray absorption near edge structure study supports a scenario of the cation-charge redistribution between Ni²⁺ and Fe³⁺ ions under the condition of an electric-field-induced in-plane compressive strain. [ABSTRACT FROM AUTHOR]