09:00 〜 09:15
▲ [19a-D104-1] [Young Scientist Presentation Award Speech] Voltage control of perpendicular magnetic anisotropy in Fe/MgAl2O4 heterostructures
キーワード:VCMA, MgAl2O4, thin films
Voltage-controlled magnetic anisotropy (VCMA) in magnetic heterostructures are expected to be a key for approaching next generation low-power consumption spintronic devices such as voltage-controlled magnetoresistive random access memories (MRAMs). For practical high-density memory applications, large interface perpendicular magnetic anisotropy (PMA) energy Ki and voltage control of magnetic anisotropy (VCMA) coefficient β, i.e., Ki > 2-3 mJ/m2 and β > 1000 fJ/(Vm), are required. To achieve such a large VCMA effect, investigating the origin of the VCMA effect using ideal PMA heterostructures without any interfacial defects appears to be necessary. In this study, we focused on the ultrathin-Fe/MgAl2O4(001) epitaxial interfaces to achieve high Ki and Ki. Especially, we investigated the Fe thickness dependence of VCMA using Fe/MgAl2O4/CoFeB orthogonally magnetized MTJs. We report that only a monolayer thickness difference has a significant impact on the PMA energy and VCMA effect.