We study the voltage control of perpendicular magnetic anisotropy in an ultrathin Fe layer sandwiched between the Cr buffer and MgO tunneling barrier layers. A high-interface magnetic anisotropy energy of $2.1\mathrm{mJ}/{\mathrm{m}}^2$ is achieved in the Cr/ultrathin $\mathrm{Fe}/\mathrm{MgO}$ structure. A large voltage-induced perpendicular magnetic anisotropy change is observed under the negative-bias voltage applications for the case of the Fe layer thinner than 0.6 nm. The amplitude of the voltage-induced anisotropy energy change exhibits a strong Fe-thickness dependence and it reaches as high as $290\mathrm{fJ}/\mathrm{Vm}$. The observed high values of the surface anisotropy and voltage-induced anisotropy energy change demonstrate the feasibility of voltage-driven spintronic devices.

• Received 17 September 2015

DOI:https://doi.org/10.1103/PhysRevApplied.5.044006