Voltage-controlled magnetic anisotropy effect through a high-k MgO/ZrO<sub>2</sub>/MgO hybrid tunneling barrier
Hiroshige Onoda, Tomohiro Nozaki, Takayuki Nozaki, Shinji Yuasa
Abstract
Abstract We investigated the voltage-controlled magnetic anisotropy (VCMA) effect in epitaxial magnetic tunnel junctions (MTJs) with a hybrid MgO/ZrO 2 /MgO tunnel barrier. A metastable cubic ZrO 2 (001) thin film was successfully grown on a MgO(001) layer, leading to the high dielectric constant of 26.5. Using the hybrid tunneling barrier, we achieved the large VCMA coefficient of −350 fJ V −1 m −1 , which is 70% larger than that observed in the magnetic tunnel junction with the single MgO barrier. Introduction of crystalline high- k dielectric tunneling barrier can open up new pathways to improving the VCMA properties in MTJs for voltage-driven spintronic devices.
Topics & Concepts
Quantum tunnellingTunnel magnetoresistanceCondensed matter physicsSpintronicsMaterials scienceMagnetic anisotropyDielectricTunnel junctionEpitaxyMetastabilityBarrier layerFerromagnetismMagnetizationLayer (electronics)NanotechnologyChemistryOptoelectronicsMagnetic fieldPhysicsOrganic chemistryQuantum mechanicsMagnetic properties of thin filmsFerroelectric and Negative Capacitance DevicesSemiconductor materials and devices