Electric field-induced magnetization switching in epitaxial columnar nanostructures

We present direct evidence for room-temperature magnetization reversal induced by an electric field in epitaxial ferroelectric BiFeO 3-ferrimagnetic CoFe 2O 4 columnar nanostructures. Piezoelectric force microscopy and magnetic force microscopy were used to locally image the coupled piezoelectric-magnetic switching. Quantitative analyses give a perpendicular magnetoelectric susceptibility of ∼1.0 × 10 -2 G cm/V. The observed effect is due to the strong elastic coupling between the two ferroic constituents as the result of the three-dimensional heteroepitaxy. © 2005 American Chemical Society.