Proximity-Induced Spin Polarization of Graphene in Contact with Half-Metallic Manganite

ACS Nano ◽  
2016 ◽  
Vol 10 (8) ◽  
pp. 7532-7541 ◽  
Author(s):  
Seiji Sakai ◽  
Sayani Majumdar ◽  
Zakhar I. Popov ◽  
Pavel V. Avramov ◽  
Shiro Entani ◽  
...  
Keyword(s):  
Spin Polarization ◽  
Half Metallic

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.

Ferromagnetic Material of the Nearly Half-Metallic Alloy Co2TiGa

2013 ◽  
Vol 690-693 ◽  
pp. 590-593 ◽  
Author(s):  
Hong Pei Han
Keyword(s):  
Spin Polarization ◽  
Heusler Alloy ◽  
Ferromagnetic Material ◽  
Full Potential ◽  
Half Metallic ◽  
Augmented Plane Wave ◽  
Plane Wave Method ◽  
Linearized Augmented Plane Wave ◽  
Full Heusler ◽  
Metallic Ferromagnetism

The structure, electronic and magnetic properties of full-Heusler alloy Co2TiGa are investigated by means of the full potential linearized augmented plane-wave method. Our results show that the ground state of Co2TiGa is of the nearly half-metallic ferromagnetism with a magnetic moment of 1.00218μBper unit cell, which are contributed by the atoms Co and Ti. Meanwhile, the spin polarization around the Fermi level is up to 93.2%, almost 100%, which indicates that full-Heusler alloy Co2TiGa with the well magnetism and spin polarization would be possibly applied to the field of the material engineering and information technology.

Room Temperature Spin Polarization of Epitaxial Half-Metallic Fe3O4(111) and CrO2(100) Films

2003 ◽  
pp. 487-504 ◽  
Author(s):  
Mikhail Fonin ◽  
Yuriy Dedkov ◽  
Christian König ◽  
Gernot Güntherodt ◽  
Ulrich Rüdiger ◽  
...  
Keyword(s):  
Spin Polarization ◽  
Room Temperature ◽  
Half Metallic

Inverse Magnetoresistance In Manganite/SrTiO3/Co Tunnel Junctions

1999 ◽  
Vol 574 ◽  
Author(s):  
J. M. De Teresa ◽  
A. Barthélémy ◽  
J. P. Contour ◽  
A. Fert ◽  
R. Lyonnet ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Fermi Level ◽  
Spin Polarization ◽  
Density Of States ◽  
High Magnetic Field ◽  
Applied Voltage ◽  
Tunnel Junctions ◽  
Effect Of Temperature ◽  
Half Metallic ◽  
Tunnel Magnetoresistance

AbstractIn La0.7Sr0.3MnO3/SrTiO3/Co tunnel junctions, the half-metallic nature of La0.7Sr0.3MnO3 allows probing the spin polarization of Co. For applied voltage bias around zero volts, an inverse tunnel magnetoresistance is found, indicating the negative spin polarization of Co at the Fermi level as expected from the density of states of the “d” band in Co. The bias dependence of the magnetoresistance reflects the structure of the “d” band density of states of Co. In this article we underline the important consequences for the knowledge of the spin-dependent tunneling in solids brought by these results and describe in detail the effect of temperature and high magnetic field on the magnetoresistance.

scholarly journals A Landau-Ginzburg Description of Sb Overlayers

2001 ◽  
Vol 674 ◽  
Author(s):  
R. Skomski ◽  
T. Komesu ◽  
H.-K. Jeong ◽  
C. N. Borca ◽  
P. A. Dowben ◽  
...  
Keyword(s):  
Spin Polarization ◽  
Heusler Alloy ◽  
Function Approximation ◽  
Gaussian Approximation ◽  
Temperature Dependent ◽  
Half Metallic ◽  
Spin Polarized ◽  
Spin Excitations ◽  
Injection Depth ◽  
Inverse Photoemission Spectroscopy

ABSTRACTThe spin polarization of Sb overlayers on the semi-Heusler alloy NiMnSb is investigated in terms of the Landau-Ginzburg approach. The half-metallic semi-Heusler alloy NiMnSb acts as a ferromagnetic perturbation and induces a spin polarization in the semimetallic Sb overlayer. Using a Gaussian approximation, the propagation of the spin perturbation in the overlayer is calculated. The results are compared with spin-polarized inverse photoemission spectroscopy (SPIPES) results and with recent spin-dependent envelope-function approximation (SDEFA) predictions. The Landau-Ginzburg parameters are both band-structure and temperature dependent, and it is argued that thermal spin excitations lead to an injection depth decreasing as 1//T law at high temperatures.

The effect of atomic structure on interface spin-polarization of half-metallic spin valves: Co2MnSi/Ag epitaxial interfaces

2015 ◽  
Vol 107 (21) ◽  
pp. 212404 ◽  
Author(s):  
Zlatko Nedelkoski ◽  
Philip J. Hasnip ◽  
Ana M. Sanchez ◽  
Balati Kuerbanjiang ◽  
Edward Higgins ◽  
...  
Keyword(s):  
Spin Polarization ◽  
Atomic Structure ◽  
Spin Valves ◽  
Half Metallic

Quantification of site disorder and its role on spin polarization in the nearly half-metallic Heusler alloy NiFeMnSn

2016 ◽  
Vol 94 (21) ◽  
Author(s):  
M. D. Mukadam ◽  
Syamashree Roy ◽  
S. S. Meena ◽  
Pramod Bhatt ◽  
S. M. Yusuf
Keyword(s):  
Spin Polarization ◽  
Heusler Alloy ◽  
Half Metallic ◽  
Site Disorder
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