Effect of annealing conditions on the perpendicular magnetic anisotropy of Ta/CoFeB/MgO multilayers

Liu, Yan; Hao, Liang; Cao, Jiangwei

doi:10.1063/1.4947132

Cited by 30 publications

(12 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3 (a), the thickness of MgO spacer within a range of 0.9 -1.25 nm had almost no influence on the fitting parameters, therefore, the values of fitting parameters 4πM ef f , g, α, and ∆H 0 are typical for all samples with various MgO thickness. Parameters determined from VNA-FMR spectra for the as-deposited in films with PMA is often strongly nonlinear due to either intermixing at interfaces [22] or magnetoelastic effects [15], with K ef f × t ef f exhibiting a maximum as a function of decreasing t ef f and with the PMA eventually being lost for small t ef f of, for example, 0.7 nm.…”

Section: Resultsmentioning

confidence: 99%

CoFeB/MgO/CoFeB structures with orthogonal easy axes: perpendicular anisotropy and damping

Głowiński

Żywczak²,

Wrona³

et al. 2017

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

We report on the Gilbert damping parameter α, the effective magnetization [Formula: see text], and the asymmetry of the g-factor in bottom-CoFeB(0.93 nm)/MgO(0.90-1.25 nm)/CoFeB(1.31 nm)-top as-deposited systems. Magnetization of CoFeB layers exhibits a specific noncollinear configuration with orthogonal easy axes and with [Formula: see text] values of [Formula: see text] kG and [Formula: see text] kG for the bottom and top layers, respectively. We show that [Formula: see text] depends on the asymmetry [Formula: see text] of the g-factor measured in the perpendicular and the in-plane directions revealing a highly nonlinear relationship. In contrast, the Gilbert damping is practically the same for both layers. Annealing of the films results in collinear easy axes perpendicular to the plane for both layers. However, the linewidth is strongly increased due to enhanced inhomogeneous broadening.

show abstract

Section: Resultsmentioning

confidence: 99%

CoFeB/MgO/CoFeB structures with orthogonal easy axes: perpendicular anisotropy and damping

Głowiński

Żywczak²,

Wrona³

et al. 2017

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

show abstract

“…This shows high potential to realize the two-domain structure in small size p-MTJs. Further, various strategies have also been reported to adjust these parameters experimentally, such as CoFeB thickness, [30,45] CoFeB composition, [46] annealing conditions, [45,46] Ta or W spacer thickness, [47] top MgO thickness, [30] inserted Mg layer between MgO and CoFeB, [48] voltage controlled magnetic anisotropy (VCMA), [43] and high order K eff . [35,44] In Figure 6d, we study the effect of the device geometry on the multi-level switching.…”

Section: Parameter Diagrams and Devices Optimizationmentioning

confidence: 99%

Multi‐Level Switching and Reversible Current Driven Domain‐Wall Motion in Single CoFeB/MgO/CoFeB‐Based Perpendicular Magnetic Tunnel Junctions

Fidalgo

Silva

et al. 2020

Adv Elect Materials

View full text Add to dashboard Cite

One of the critical issues in spintronics‐based technologies is to increase the data storage density. Current strategy is based on shrinking the devices size down to tens of nanometers, or several nanometers, which is reaching its limit. A new proposal is to use multi‐level cells (MLCs) to store more than two bits in each cell. In this work, the multi‐level switching is realized in CoFeB/MgO/CoFeB based nano‐scale single perpendicular magnetic tunnel junctions (p‐MTJs) with three or four stable resistance states. A large range of writing currents for each state is obtained, accompanying with a good repeatability of set‐reset operations between different states. The developed multi‐domain model perfectly matches the experimental results, reflecting the magnetic behaviors during multi‐level switching. Furthermore, current‐driven domain wall (DW) motion is revealed in the circular p‐MTJs, where the DW position can be reversibly manipulated by applied current. To design high‐performance multi‐level p‐MTJs, the parameter diagrams are calculated, suggesting various feasible strategies to improve the multi‐level switching through materials optimization and devices geometry. In summary, the demonstration of multi‐level switching in single p‐MTJ shows the high potential of realizing the new generation of p‐MTJ‐based multi‐level spintronic devices, such as multi‐level memories and spin‐neuron devices.

show abstract

“…To investigate the effect of MgO film thickness at various temperatures on the magnetic anisotropy of MgO/CFA/ t MgO /Mo, we determine the K eff by using the relation

K_{e f f} = \frac{M_{normalS} \times H_{normalK}}{2}

where M S and H K are the saturation magnetization of CFA layer (either in‐plane or perpendicular to the film) and uniaxial perpendicular anisotropy field, respectively. K eff mainly originates from the bulk and interface anisotropy and is usually described by the equation

K_{e f f} = K_{normalV} - 2 π M_{normalS}^{2} + \frac{K_{normali}}{t_{C {normalo}_{2} F e A l}}

…”

Section: Resultsmentioning

confidence: 99%

“…where M S and H K are the saturation magnetization of CFA layer (either in-plane or perpendicular to the film) and uniaxial perpendicular anisotropy field, respectively. K eff mainly originates from the bulk and interface anisotropy and is usually described by the equation [45,46]…”

Section: Resultsmentioning

confidence: 99%

Robust Perpendicular Magnetic Anisotropy in MgO/Co₂FeAl/MgO Stacks Induced by MgO over Layer and Annealing Temperature

Saravanan

Muthuvel

Delhibabu

et al. 2018

Physica Status Solidi (a)

View full text Add to dashboard Cite

Perpendicular magnetic anisotropy (PMA) in Co2FeAl (CFA)/MgO stacks deposited on the MgO buffer layer is studied as a function of MgO over‐layer thickness and annealing temperature. It reveals that MgO over‐layer (thickness between 0 and 1.5 nm) improves the PMA of CFA grown on MgO buffer layer. It is identified that MgO over‐layer thickness is a crucial factor that affects the magnetic anisotropy. The maximum effective PMA energy density (Keff) of ≈1.22 × 106 erg cm−3 is observed at 400 °C. Besides, PMA is also realized for room temperature (RT) films. Moreover, enhancement in the perpendicular saturation magnetization (Ms┴) with PMA is effectively induced by the CFA/MgO or CFA/Mo interface and is discussed in detail. The grain distribution and surface roughness are investigated by atomic force microscopy (AFM) for without and with MgO over‐layer in MgO/CFA/tMgO (0 and 0.5 nm)/Mo stacks at higher annealing temperature. Therefore, this MgO/CFA/MgO can be an ideal system for the p‐MTJs‐based new generation low power consuming large density data storage spintronic devices with improved thermal stability.

show abstract

Effect of annealing conditions on the perpendicular magnetic anisotropy of Ta/CoFeB/MgO multilayers

Cited by 30 publications

References 21 publications

CoFeB/MgO/CoFeB structures with orthogonal easy axes: perpendicular anisotropy and damping

CoFeB/MgO/CoFeB structures with orthogonal easy axes: perpendicular anisotropy and damping

Multi‐Level Switching and Reversible Current Driven Domain‐Wall Motion in Single CoFeB/MgO/CoFeB‐Based Perpendicular Magnetic Tunnel Junctions

Robust Perpendicular Magnetic Anisotropy in MgO/Co₂FeAl/MgO Stacks Induced by MgO over Layer and Annealing Temperature

Contact Info

Product

Resources

About

Effect of annealing conditions on the perpendicular magnetic anisotropy of Ta/CoFeB/MgO multilayers

Cited by 30 publications

References 21 publications

CoFeB/MgO/CoFeB structures with orthogonal easy axes: perpendicular anisotropy and damping

CoFeB/MgO/CoFeB structures with orthogonal easy axes: perpendicular anisotropy and damping

Multi‐Level Switching and Reversible Current Driven Domain‐Wall Motion in Single CoFeB/MgO/CoFeB‐Based Perpendicular Magnetic Tunnel Junctions

Robust Perpendicular Magnetic Anisotropy in MgO/Co2FeAl/MgO Stacks Induced by MgO over Layer and Annealing Temperature

Contact Info

Product

Resources

About

Robust Perpendicular Magnetic Anisotropy in MgO/Co₂FeAl/MgO Stacks Induced by MgO over Layer and Annealing Temperature