Magnetic Properties of Electrodeposited FeGa/CoFeB Multilayered Films and Nanowire Arrays

Results concerning the preparation and magnetic characterization of electrochemically deposited [Fe₈₀ Ga₂₀ /Co₇₅ Fe₁₀ B₁₅ ]_n multilayered films and nanowire arrays are reported for the first time. The deposition bath consisted in a single mixed solution of FeSO₄middot7H₂O, Ga₂(SO₄)₃middotH₂O, CoSO₄middot7H₂O, C₂H ₁₀BN, and H₃BO₃. The layers have been deposited successively by changing the electrodeposition potential. The composition and thickness of the different layers were tailored through optimizing deposition parameters such as buffer additives and applied voltage. Two hundred sequences multilayered nanowires were electrodeposited into commercially available nanoporous alumina membranes with pore diameters of 100 nm and lengths of 50 mum. Multilayered films 4-5 mu m thick have been obtained by electrodepositing 50 consecutive sequences of FeGa and CoFeB. The multilayered structures consisting FeGa magnetostrictive alloy and CoFeB amorphous magnetic material are magnetically soft (H_c does not exceed 1.6 kA/m).