Tunneling spin polarization measurements from ferromagnet/MgO tunnel junctions using NbN superconductor

2006 ◽  
Vol 88 (18) ◽  
pp. 182501 ◽  
Author(s):  
Hyunsoo Yang ◽  
See-Hun Yang ◽  
Christian Kaiser ◽  
Stuart Parkin
Keyword(s):  
Spin Polarization ◽  
Tunnel Junctions ◽  
Polarization Measurements

Magnetism and Spin Tunneling in Nanostructures

1997 ◽  
Vol 491 ◽  
Author(s):  
Alexander Bratkovsky
Keyword(s):  
Spin Polarization ◽  
Tunnel Junctions ◽  
Iron Group ◽  
Defect States ◽  
Resistance Change ◽  
Half Metallic ◽  
Spin Tunneling ◽  
Inelastic Tunneling ◽  
Resonant Tunnel ◽  
General Method

ABSTRACTIn the present paper different tunneling mechanisms in conventional and half-metallic ferromagnetic tunnel junctions are analyzed within the same general method. Theoretically calculated direct tunneling in iron group systems leads to about a 30% change in resistance, which is close but lower than experimentally observed values. It is shown that the larger observed values of the TMR might be a result of tunneling involving surface polarized states. We find that tunneling via resonant defect states in the barrier radically decreases the TMR (down to 4% with Fe-based electrodes), and a resonant tunnel diode structure would give a TMR of about 8%. With regards to inelastic tunneling, magnons and phonons exhibit opposite effects: one-magnon emission generally results in spin mixing and, consequently, reduces the TMR, whereas phonons are shown to enhance the TMR. The inclusion of both magnons and phonons reasonably explains an unusual bias dependence of the TMR.The model presented here is applied qualitatively to half-metallics with 100% spin polarization, where one-magnon processes are suppressed and the change in resistance in the absence of spin-mixing on impurities may be arbitrarily large. Even in the case of imperfect magnetic configurations, the resistance change can be a few 1000 percent. Examples of half-metallic systems are CrO2/TiO2 and CrO2/RuO2, and an account of their peculiar band structures is presented. The implications and relation of these systems to CMR materials, which are nearly half-metallic, are discussed.

scholarly journals Effect of modified periodic waveforms on current-induced spin polarization measurements

AIP Advances ◽  
2018 ◽  
Vol 8 (6) ◽  
pp. 065113
Author(s):  
Joseph R. Iafrate ◽  
Simon Huang ◽  
Davide Del Gaudio ◽  
Rachel S. Goldman ◽  
Vanessa Sih
Keyword(s):  
Spin Polarization ◽  
Polarization Measurements

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.

Quenching of Spin Polarization Switching in Organic Multiferroic Tunnel Junctions by Ferroelectric “Ailing-Channel” in Organic Barrier

2018 ◽  
Vol 10 (36) ◽  
pp. 30614-30622 ◽  
Author(s):  
Shiheng Liang ◽  
Zhongwei Yu ◽  
Xavier Devaux ◽  
Anthony Ferri ◽  
Weichuan Huang ◽  
...  
Keyword(s):  
Spin Polarization ◽  
Tunnel Junctions ◽  
Polarization Switching

Magnetoresistance and spin polarization of electron current in magnetic tunnel junctions

2007 ◽  
Vol 75 (17) ◽  
Author(s):  
N. N. Beletskii ◽  
G. P. Berman ◽  
A. R. Bishop ◽  
S. A. Borysenko ◽  
V. M. Yakovenko
Keyword(s):  
Spin Polarization ◽  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Electron Current

scholarly journals Sign reversal of spin polarization inCo/Ru/Al2O3/Comagnetic tunnel junctions

2001 ◽  
Vol 64 (10) ◽  
Author(s):  
P. LeClair ◽  
B. Hoex ◽  
H. Wieldraaijer ◽  
J. T. Kohlhepp ◽  
H. J. M. Swagten ◽  
...  
Keyword(s):  
Spin Polarization ◽  
Tunnel Junctions ◽  
Sign Reversal
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