scholarly journals THE IMPORTANCE OF Fe SURFACE STATES FOR MAGNETIC TUNNEL JUNCTION BASED SPINTRONIC DEVICES

2008 ◽  
Vol 22 (26) ◽  
pp. 2529-2551 ◽  
Author(s):  
ATHANASIOS N. CHANTIS ◽  
KIRILL D. BELASHCHENKO ◽  
EVGENY Y. TSYMBAL ◽  
INNA V. SUS
Keyword(s):  
Spin Polarization ◽  
Tunnel Junctions ◽  
Strong Dependence ◽  
Magnetic Tunnel Junctions ◽  
Interface States ◽  
Tunneling Magnetoresistance ◽  
Sign Reversal ◽  
Spintronic Devices ◽  
Spin Electronics ◽  
Minority Spin

In this article we give a review of our recent theoretical studies of the influence of Fe (001) surface (interface) states on spin-polarized electron transport across magnetic tunnel junctions with Fe electrodes. We show that minority-spin surface (interface) states are responsible for at least two effects which are important for spin electronics. First, they can produce a sizable tunneling anisotropic magnetoresistance in magnetic tunnel junctions with a single Fe electrode. The effect is driven by a Rashba shift of the resonant surface band when the magnetization changes direction. This can introduce a new class of spintronic devices, namely, tunneling magnetoresistance junctions with a single ferromagnetic electrode. Second, in Fe/GaAs (001) magnetic tunnel junctions minority-spin interface states produce a strong dependence of the tunneling current spin polarization on applied electrical bias. A dramatic sign reversal within a voltage range of just a few tenths of an eV is predicted. This explains the observed sign reversal of spin polarization in recent experiments of electrical spin injection in Fe/GaAs (001) and related reversal of tunneling magnetoresistance through vertical Fe/GaAs/Fe trilayers.

Spin-filtering and tunneling magnetoresistance effects in 6,6,12-graphyne-based molecular magnetic tunnel junctions

2019 ◽  
Vol 21 (5) ◽  
pp. 2734-2742 ◽  
Author(s):  
Jin Li ◽  
Maoyun Di ◽  
Zhi Yang ◽  
Li-Chun Xu ◽  
Yongzhen Yang ◽  
...  
Keyword(s):  
Tunnel Junctions ◽  
Graphene Nanoribbons ◽  
Magnetic Tunnel Junctions ◽  
Tunneling Magnetoresistance ◽  
Spintronic Devices ◽  
Zigzag Graphene Nanoribbons ◽  
Spin Filtering

By designing two kinds of molecular magnetic tunnel junctions based on 6,6,12-graphyne and zigzag graphene nanoribbons, the spin-filtering and tunneling magnetoresistance effects of spintronic devices can be dramatically enhanced.

scholarly journals Spin-neutral currents for spintronics

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ding-Fu Shao ◽  
Shu-Hui Zhang ◽  
Ming Li ◽  
Chang-Beom Eom ◽  
Evgeny Y. Tsymbal
Keyword(s):  
Fermi Surface ◽  
Spin Polarization ◽  
Tunnel Junctions ◽  
Relative Orientation ◽  
Group Symmetry ◽  
Tunneling Magnetoresistance ◽  
Neutral Currents ◽  
Spintronic Devices ◽  
Normal Metals ◽  
Antiferromagnetic Layer

AbstractElectric currents carrying a net spin polarization are widely used in spintronics, whereas globally spin-neutral currents are expected to play no role in spin-dependent phenomena. Here we show that, in contrast to this common expectation, spin-independent conductance in compensated antiferromagnets and normal metals can be efficiently exploited in spintronics, provided their magnetic space group symmetry supports a non-spin-degenerate Fermi surface. Due to their momentum-dependent spin polarization, such antiferromagnets can be used as active elements in antiferromagnetic tunnel junctions (AFMTJs) and produce a giant tunneling magnetoresistance (TMR) effect. Using RuO2 as a representative compensated antiferromagnet exhibiting spin-independent conductance along the [001] direction but a non-spin-degenerate Fermi surface, we design a RuO2/TiO2/RuO2 (001) AFMTJ, where a globally spin-neutral charge current is controlled by the relative orientation of the Néel vectors of the two RuO2 electrodes, resulting in the TMR effect as large as ~500%. These results are expanded to normal metals which can be used as a counter electrode in AFMTJs with a single antiferromagnetic layer or other elements in spintronic devices. Our work uncovers an unexplored potential of the materials with no global spin polarization for utilizing them in spintronics.

scholarly journals Surface acoustic wave induced modulation of tunneling magnetoresistance in magnetic tunnel junctions

2021 ◽  
Vol 130 (3) ◽  
pp. 033901
Author(s):  
Dhritiman Bhattacharya ◽  
Peng Sheng ◽  
Md Ahsanul Abeed ◽  
Zhengyang Zhao ◽  
Hongshi Li ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Tunneling Magnetoresistance ◽  
Wave Induced

MAGNETORESISTANCE IN Fe/MgO/Fe MAGNETIC TUNNEL JUNCTIONS

2007 ◽  
Vol 17 (03) ◽  
pp. 593-598 ◽  
Author(s):  
N. N. BELETSKII ◽  
S. A. BORYSENKO ◽  
V. M. YAKOVENKO ◽  
G. P. BERMAN ◽  
S. A. WOLF
Keyword(s):  
Current Density ◽  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Tunneling Magnetoresistance ◽  
Electron Current ◽  
Ferromagnetic Electrode ◽  
Electron Current Density

The magnetoresistance of Fe/MgO/Fe magnetic tunnel junctions (MTJs) was studied taking into consideration image forces. For MTJs with an MgO insulator, explanations are given of the giant tunneling magnetoresistance (TMR) effect and the effect of the increasing TMR with an increase in MgO insulator thickness. It is demonstrated that the electron current density through MTJs can be high enough to switch the magnetization of a ferromagnetic electrode.

Oscillation of giant tunneling magnetoresistance with respect to tunneling barrier thickness in fully epitaxial Fe∕MgO∕Fe magnetic tunnel junctions

2007 ◽  
Vol 90 (25) ◽  
pp. 252506 ◽  
Author(s):  
Rie Matsumoto ◽  
Akio Fukushima ◽  
Taro Nagahama ◽  
Yoshishige Suzuki ◽  
Koji Ando ◽  
...  
Keyword(s):  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Tunneling Magnetoresistance ◽  
Barrier Thickness ◽  
Tunneling Barrier

Ferromagnetic barrier induced large enhancement of tunneling magnetoresistance in van der Waals perpendicular magnetic tunnel junctions

Nanoscale ◽  
2021 ◽  
Author(s):  
Xiaolin Zhang ◽  
Baishun Yang ◽  
Xiaoyan Guo ◽  
Xiufeng Han ◽  
Yu Yan
Keyword(s):  
Tunnel Junctions ◽  
Van Der Waals ◽  
Magnetic Tunnel Junctions ◽  
Tunneling Magnetoresistance ◽  
Large Enhancement

Schematics of TMR effect of FGT/CrI3/FGT and FGT/ScI3/FGT vdW MTJs.

Tunneling magnetoresistance and light modulation in Fe4N(La2/3Sr1/3MnO3)/C60/Fe4N single molecule magnetic tunnel junctions

2020 ◽  
Vol 8 (9) ◽  
pp. 3137-3146 ◽  
Author(s):  
Xuefei Han ◽  
Wenbo Mi ◽  
Dunhui Wang
Keyword(s):  
Transport Properties ◽  
Single Molecule ◽  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Tunneling Magnetoresistance ◽  
Light Modulation ◽  
Spin Dependent Transport ◽  
Dependent Transport

Spin-dependent transport properties and light modulation of Fe4N/C60/Fe4N and LSMO/C60/Fe4N single molecule magnetic tunnel junctions.

Role of Metal-Oxide Interface in Determining the Spin Polarization of Magnetic Tunnel Junctions

Science ◽  
1999 ◽  
Vol 286 (5439) ◽  
pp. 507-509 ◽  
Author(s):  
Jose Maria De Teresa ◽  
Agnès Barthélémy ◽  
Albert Fert ◽  
Jean Pierre Contour ◽  
François Montaigne ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Metal Oxide ◽  
Spin Polarization ◽  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Ferromagnetic Transition ◽  
Oxide Interface ◽  
Oxide Interfaces ◽  
Structure Of Metal

The role of the metal-oxide interface in determining the spin polarization of electrons tunneling from or into ferromagnetic transition metals in magnetic tunnel junctions is reported. The spin polarization of cobalt in tunnel junctions with an alumina barrier is positive, but it is negative when the barrier is strontium titanate or cerium lanthanite. The results are ascribed to bonding effects at the transition metal–barrier interface. The influence of the electronic structure of metal-oxide interfaces on the spin polarization raises interesting fundamental problems and opens new ways to optimize the magnetoresistance of tunnel junctions.

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