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Title: Resonant TMR inversion in LiF/EuS based spin-filter tunnel junctions

Abstract

Resonant tunneling can lead to inverse tunnel magnetoresistance when impurity levels rather than direct tunneling dominate the transport process. We fabricated hybrid magnetic tunnel junctions of CoFe/LiF/EuS/Ti, with an epitaxial LiF energy barrier joined with a polycrystalline EuS spin-filter barrier. Due to the water solubility of LiF, the devices were fully packaged in situ. The devices showed sizeable positive TMR up to 16% at low bias voltages but clearly inverted TMR at higher bias voltages. The TMR inversion depends sensitively on the thickness of LiF, and the tendency of inversion disappears when LiF gets thick enough and recovers its intrinsic properties.

Authors:
;  [1];  [2]; ; ; ;  [3]
  1. East China Jiaotong University, Department of Science, Nanchang, Jiangxi 330013 (China)
  2. (Canada)
  3. Institute for Quantum Computing & Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, ON N2L 3G1 Canada (Canada)
Publication Date:
OSTI Identifier:
22611413
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 6; Journal Issue: 8; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; DIFFUSION BARRIERS; EPITAXY; EUROPIUM SULFIDES; FILTERS; IMPURITIES; LITHIUM FLUORIDES; MAGNETIC TUNNEL JUNCTIONS; MAGNETORESISTANCE; POLYCRYSTALS; SPIN; THICKNESS; TUNNEL EFFECT; WATER

Citation Formats

Liu, Fen, Chen, Aixi, Institute for Quantum Computing & Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, ON N2L 3G1 Canada, Yang, Yihang, Xue, Qian, Gao, Zhiwei, and Miao, Guo-Xing, E-mail: guo-xing.miao@uwaterloo.ca. Resonant TMR inversion in LiF/EuS based spin-filter tunnel junctions. United States: N. p., 2016. Web. doi:10.1063/1.4960837.
Liu, Fen, Chen, Aixi, Institute for Quantum Computing & Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, ON N2L 3G1 Canada, Yang, Yihang, Xue, Qian, Gao, Zhiwei, & Miao, Guo-Xing, E-mail: guo-xing.miao@uwaterloo.ca. Resonant TMR inversion in LiF/EuS based spin-filter tunnel junctions. United States. doi:10.1063/1.4960837.
Liu, Fen, Chen, Aixi, Institute for Quantum Computing & Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, ON N2L 3G1 Canada, Yang, Yihang, Xue, Qian, Gao, Zhiwei, and Miao, Guo-Xing, E-mail: guo-xing.miao@uwaterloo.ca. 2016. "Resonant TMR inversion in LiF/EuS based spin-filter tunnel junctions". United States. doi:10.1063/1.4960837.
@article{osti_22611413,
title = {Resonant TMR inversion in LiF/EuS based spin-filter tunnel junctions},
author = {Liu, Fen and Chen, Aixi and Institute for Quantum Computing & Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, ON N2L 3G1 Canada and Yang, Yihang and Xue, Qian and Gao, Zhiwei and Miao, Guo-Xing, E-mail: guo-xing.miao@uwaterloo.ca},
abstractNote = {Resonant tunneling can lead to inverse tunnel magnetoresistance when impurity levels rather than direct tunneling dominate the transport process. We fabricated hybrid magnetic tunnel junctions of CoFe/LiF/EuS/Ti, with an epitaxial LiF energy barrier joined with a polycrystalline EuS spin-filter barrier. Due to the water solubility of LiF, the devices were fully packaged in situ. The devices showed sizeable positive TMR up to 16% at low bias voltages but clearly inverted TMR at higher bias voltages. The TMR inversion depends sensitively on the thickness of LiF, and the tendency of inversion disappears when LiF gets thick enough and recovers its intrinsic properties.},
doi = {10.1063/1.4960837},
journal = {AIP Advances},
number = 8,
volume = 6,
place = {United States},
year = 2016,
month = 8
}
  • The orbital composition of the electrode wave functions and the complex bands within the barrier band gap are two important factors in deciding the spin-filter effect. This is illustrated in a class of spinel oxides, including MgAl2O4, ZnAl2O4, SiMg2O4, and SiZn2O4. Through first-principles calculations of the complex bands and electron transmission along the [001] direction, they are shown to have the same D1 spin-filter effect as MgO due to the combination of both factors. Due to better lattice match with typical bcc magnetic electrodes than MgO, these materials provide a broad spectrum of candidate materials for magnetic tunnel junctions.
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  • No abstract prepared.
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