Voltage control of perpendicular magnetic anisotropy in (Co/Pt)₃/Pb(Zn_1/3Nb_2/3)O₃-PbTiO₃ multiferroic heterostructures at room temperature

Voltage control of perpendicular magnetic anisotropy (PMA) in ferromagnetic/ferroelectric multiferroic heterostructures is a promising method to enable high density and low power perpendicular magnetic information storage. In this study, we successfully achieved large voltage tuning of PMA at room temperature in (Co/Pt)₃/Pb(Zn_1/3Nb_2/3)O₃-PbTiO₃ (PZN-PT) multiferroic heterostructures. Voltage tuning of magnetic anisotropy and the magnetoelectric coupling effect has been qualitatively studied by ferromagnetic resonance, and the multiferroic heterostructure could be reversibly flipped between two distinct PMA states under zero or high electric fields. During the linear piezo-strain response of PZN-PT, the multiferroic heterostructures exhibit small magnetoelectric coupling and the electric field-induced magnetic anisotropy field was about 295 Oe. During the electric field-induced phase transition of PZN-PT, voltage tuning of PMA enhanced more than two times that of the first linear region and the electric field-induced magnetic anisotropy field increased to 634 Oe. Finally, this magnetoelectric coupling was enhanced to 672 Oe by applying 12 kV/cm, corresponding to a large magnetoelectric coupling coefficient up to 56 Oe·cm/kV. Benefiting from the giant strain response during voltage-induced phase transition in PZN-PT, voltage tuning of PMA in those multiferroic heterostructures is a promising candidate for power-efficient magnetic memories.