Electric-field-induced magnetic domain wall motion in bilayer FeGa/BaTiO3 thin film structures*

We have studied electromechanical coupling induced magnetic domain motion in unclamped FeGa/BaTiO3 thin film bilayer structures. Magnetostrictive FeGa layers were sputter-deposited on epitaxially grown BaTiO3 films on SrTiO3 substrates. Focused ion-beam milling was used to remove the substrate from underneath the BaTiO3 film, and electrodes were patterned in the metallic FeGa film to apply electric field across a patterned gap (1 micron). Lorentz microscopy was used to monitor the magnetic domains in FeGa, while electric field is applied to the piezoelectric BaTiO3. Lorentz microscopy allows direct and dynamic observation of magnetic domain motions. Reversible electric field induced magnetic domain motion was observed, and the results will be compared to micromagnetic simulations of the domain wall structure.