Voltage-Controlled Magnetization Reversal of 100-nm-Thick Magnetic Layer Characterized by Micromagnetic Simulation

We investigated magnetic switching of relatively thick (~100 nm) magnetic film using voltage-controlled magnetic anisotropy (VCMA). Our micromagnetic simulation study clarified two crucial points: the magnetic layer has a ferromagnetic bilayer structure composed of a thin and thick layer, and each layer has a different perpendicular magnetic anisotropy (PMA). The thin layer is attached to a dielectric layer, which changes the magnetic anisotropy of the thin layer by VCMA effect. We also found that the thick magnetic layer was switched by the VCMA in the thin layer (VCMA coefficient = −60 fJ/Vm) when the effective PMA field of the thick magnetic layer is smaller than 3 × 105 A/m. In the thick magnetic layer, the entire layer was switched by the reduction of magnetic anisotropy in the thin magnetic layer. This finding may open up new applications, such as magneto-optical spatial light modulators (MO-SLMs), which require thick magnetic layers for a larger MO effect.