Magnetoresistance Variation of Magnetic Tunnel Junctions with NiFeSiB/CoFeB Free Layers Depending on MgO Tunnel Barrier Thickness

We developed NiFeSiB/CoFeB hybrid free-layers for magnetic tunnel junctions (MTJs) with MgO tunnel barrier layers. These junctions show tunneling magnetoresistance (TMR) ratios and resistance-area (RA) values ranging from 118-209% and 36-2380 Omega mum 2 , respectively, obtained at room temperature....

Full description

Saved in:
Bibliographic Details
Published in:IEEE transactions on magnetics 2008-11, Vol.44 (11), p.2547-2550
Main Authors: Ji Ung Cho, Do Kyun Kim, Tian Xing Wang, Isogami, S., Tsunoda, M., Takahashi, M., Young Keun Kim
Format: Article
Language:English
Subjects:
Anisotropic magnetoresistance
Barriers
Cross-disciplinary physics: materials science
rheology
Current density
Exact sciences and technology
Hybrid free layer
Iron
low saturation magnetization
Magnesium oxide
Magnetic materials
Magnetic switching
magnetic tunnel junction
Magnetic tunneling
Magnetism
Magnetoresistance
Magnetoresistivity
Materials science
NiFeSiB
Other topics in materials science
Physics
Saturation (magnetic)
Saturation magnetization
Switching
Temperature
Tunnel junctions
Tunneling magnetoresistance
Tunnels (transportation)
Writing
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We developed NiFeSiB/CoFeB hybrid free-layers for magnetic tunnel junctions (MTJs) with MgO tunnel barrier layers. These junctions show tunneling magnetoresistance (TMR) ratios and resistance-area (RA) values ranging from 118-209% and 36-2380 Omega mum 2 , respectively, obtained at room temperature. Compared to the CoFeB single free-layer case, the NiFeSiB/CoFeB hybrid free-layer approach has the advantage of lowering saturation magnetization. The low magnetization material would be effective to decrease the switching current in spin transfer torque (STT) switching. The experimental results show that the RA value depends not only on the thickness of the MgO barrier but also on the structure of the free layer used. Tunable in the TMR ratio and RA value using the design of the hybrid free-layer, our hybrid free-layered MTJs demonstrate a desirable lower RA value but a similar TMR ratio in comparison to the CoFeB free-layered ones.
ISSN:0018-9464
1941-0069
DOI:10.1109/TMAG.2008.2003244