Electric Field Control of Fe Nano Magnets: Magnetoelectric Coupling at Metal Surfaces

Magnetoelectric coupling at metal surfaces opens up a new possibility for metallic non-volatile magnetic data-storage devices, in which the magnetic bits are controlled by an electric field. We studied the atomic and magnetic order in bilayer Fe nano-islands grown on a Cu(111) substrate with a scanning tunneling microscopy setup in ultra-high vacuum at 4.5 K. Electric field pulses (108-109 V/m) were found to be able to cause a displacement of the Fe atoms, switching simultaneously the crystalline and the magnetic order, which is the prove of magnetoelectric coupling at the metallic Fe surface. We also succeeded in controlling the direction of the switching by the polarity of the electric field.