Magnetoelectric coupling in self-assembled BiFeO3-CoFe2O4nanocomposites on (110)-LaAlO3substrates

Abstract

We describe the magnetic domain structures and magnetoelectric coupling in self-assembled BiFeO3-CoFe2O4 (BFO-CFO) nanocomposite thin films grown on (110)-LaAlO3 substrates, consisting of CFO slab-shaped crystals (nanofins) embedded in a BFO matrix. The nanofins exhibit magnetic single-domain states with in-plane magnetization along their length due to shape and magnetoelastic anisotropies. The piezoresponse of the BFO matrix is affected by applying an in-plane hard axis magnetic field, indicating magnetoelectric coupling within the multiferroic composite. Conversely, an applied electric field leads to the magnetic reversal of a fraction of the nanofins as the strain transferred from the BFO alters the magnetic anisotropy, enabling switching driven by magnetostatic interactions.