Voltage-dependent ferromagnetic resonance in epitaxial multiferroic nanocomposites

We demonstrate electrical control of the ferromagnetic resonance (FMR) in multiferroic nanostructures. A series of heteroepitaxial BiFeO 3-NiFe2O4 nanocomposites of varying thickness are characterized using a microwave probe with magnetic and electric sensitivity. We apply an electric field to a sample and observe voltage-driven shifts in the FMR frequency, reflecting a change in magnetic anisotropy. The voltage dependence of the FMR linewidths is even more pronounced, indicating the electric polarization can induce relatively large magnetic nonuniformity in the material. These characteristics may lead to a class of rf filters where both frequency and bandwidth are electrically tunable. © 2010 American Institute of Physics.