Voltage-control of the in-plane magnetic anisotropy in hybrid magnetoelectric Ni90Fe10/BaTiO3(011) heterostructures

Abstract

This study focuses on hybrid magnetoelectric Ni₉₀Fe₁₀/BaTiO₃(011) heterostructures, which enable the control of the in-plane magnetization of the magnetostrictive layer through electric voltage. The heterostructure is both Pb- and rare-earth-free, thus enhancing environmental sustainability. We show that the BaTiO₃(011) orientation enables higher deformations in the piezoelectric regime compared to the commonly studied (001) orientation. In the as-grown state, the electrodeposited 200 nm-thick Ni₉₀Fe₁₀ film presents uniaxial in-plane anisotropy aligned with the [100] in-plane crystallographic direction of the BaTiO₃(011) substrate. X-ray magnetic circular dichroism photoemission electron microscopy images, along with hysteresis loops obtained by the magneto-optical Kerr effect, confirm the converse magnetoelectric coupling between Ni₉₀Fe₁₀ and BaTiO₃(011). The obtained converse magnetoelectric coupling constant of 0.205 μs m⁻¹ is significant considering it is achieved in the piezoelectric regime of the BaTiO₃ substrate and using an electrodeposited magnetostrictive film, making this heterostructure more viable for future applications. This value represents an increase of more than double compared to that previously reported for Ni/BTO(001) and, to the best of our knowledge, is the first value reported for the BTO(011) orientation.