Large nonvolatile control of interfacial magnetic anisotropy in CoPt by a ferroelectric ZnO-based tunneling barrier

Abstract

The electric control of magnetic anisotropy has important applications for nonvolatile memory and information processing. By first-principles calculations, we show a large nonvolatile control of magnetic anisotropy in ferromagnetic/ferroelectric CoPt/ZnO interface. Using the switched electric polarization of ZnO, the density-of-states and magnetic anisotropy at the CoPt surface show a large change. Due to a strong Co/Pt orbitals hybridization and a large spin-orbit coupling, a large control of magnetic anisotropy was found. We experimentally measured the change of effective anisotropy by tunneling resistance measurements in CoPt/Mg-doped ZnO/Co junctions.Additionally, we corroborate the origin of the control of magnetic anisotropy by observations on tunneling anisotropic magnetoresistance. 77.55.hf,77.55.fp,85.30.Mn

Route towards efficient magnetization reversal driven by voltage control of magnetic anisotropy

“…For the macrospin simulations, we considered a ferromagnetic disk of thickness t = 0.9 nm, saturation magnetization M s = 1000 kA/m and an out-of-plane effective anisotropy field of µ 0 H K = 80 mT. These parameters are rather usual values for ferromagnetic thin films exhibiting perpendicular magnetic anisotropy (PMA) 29 , 30 and particularly, they are typical for heavy-metal/ferromagnet/oxide systems most common in VCMA studies 14 , 21 , 31 , 32 . This model satisfies magnetic entities with lateral dimensions bellow the domain wall width, which in this case is around 72 nm.…”

Route Towards Efficient Magnetization Reversal Driven by Voltage Control of Magnetic Anisotropy

“…For the macrospin simulations, we considered a ferromagnetic disk of thickness t=0.9 nm, saturation magnetization Ms=1000 kA/m and an out-of-plane effective anisotropy field of µ0HK=80mT. These parameters are rather usual values for ferromagnetic thin films exhibiting perpendicular magnetic anisotropy (PMA) [30] [31] and particularly, they are typical for heavy-metal/ferromagnet/oxide systems most common in VCMA studies [32] [15] [22] [33]. This model satisfies magnetic entities with lateral dimensions bellow the domain wall width, which in this case is around 72 nm.…”