Gate-tunable high magnetoresistance in monolayer Fe3GeTe2 spin valves

2020 ◽  
Vol 22 (44) ◽  
pp. 25730-25739
Author(s):  
Jie Yang ◽  
Ruge Quhe ◽  
Shiqi Liu ◽  
Yuxuan Peng ◽  
Xiaotian Sun ◽  
...  
Keyword(s):  
Spin Valve ◽  
Spin Valves ◽  
Ferromagnetic Electrodes

Here we design a monolayer Fe3GeTe2 spin-valve device by attaching two ends to ferromagnetic electrodes. A high magnetoresistance of ~ 390% is obtained and significantly increased to 450 ~ 510% after the gates are introduced.

Towards a Room Temperature Organic Spin Valve: Structural, Magnetic and Transport Properties of Fe3O4/PTCTE/Co Devices

2011 ◽  
Vol 1359 ◽  
Author(s):  
Mathieu Palosse ◽  
Elena Bedel-Pereira ◽  
François Olivié ◽  
Isabelle Séguy ◽  
Christina Villeneuve ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Current Distribution ◽  
Morphological Study ◽  
Room Temperature ◽  
Spin Valve ◽  
Vibrating Sample Magnetometer ◽  
Force Microscopy ◽  
Dc Sputtering ◽  
Ferromagnetic Electrodes ◽  
Atomic Force

ABSTRACTThis paper describes first steps in preparation of an organic spin valve based on a perylene derivative (PTCTE) sandwiched between magnetite (Fe3O4) and cobalt (Co) ferromagnetic electrodes. MgO(001)/Fe3O4/PTCTE (450 nm)/Co devices were prepared with different Co soft deposition methods: off-axis dc-sputtering or Joule evaporation. Vibrating Sample Magnetometer (VSM) studies of the Fe3O4/PTCTE/Co stacks evidence spin valve behavior with magnetically uncoupled electrodes. These results are correlated with a morphological study by atomic force microscopy (AFM) of each layer and tunneling AFM (TUNA) for the investigation of inhomogeneity of current distribution in the devices. Finally, macroscopic I-V characteristics performed on the same devices will be presented and compared with TUNA results.

Giant Magnetoresistance Induced by Ultrathin Magnetic Layers

1997 ◽  
Vol 475 ◽  
Author(s):  
G.J. Strijkers ◽  
H.J.M. Swagten ◽  
A.H.M. Mettler ◽  
M.M.H. Willekens ◽  
W.J.M. De Jonge
Keyword(s):  
Giant Magnetoresistance ◽  
Spin Valve ◽  
Short Length ◽  
Spin Valves ◽  
Length Scale ◽  
Magnetic Layers ◽  
Ferromagnetic Layers ◽  
Experimental Tool ◽  
Spin Dependent Scattering

ABSTRACTWe introduce an interface selective structure, composed of a spin-valve on top of which a thick nonmagnetic back layer is deposited as a straightforward experimental tool to measure the GMR induced by ultrathin magnetic layers. The interface selectivity of spin-dependent scattering is evidenced by calculations and illustrated in both Co/Cu/Co and Ni80Fe20/Cu/Ni80Fe20 spin-valves by an almost discontinuous behavior in the GMR ratio. The temperture dependence of the extremely short length scale associated with this discontinuity is discussed in relation to the structure of ultrathin ferromagnetic layers.

Spin Valves in Microelectronics. Review

2021 ◽  
Vol 26 (1) ◽  
pp. 7-29
Author(s):  
Iu.A. Iusipova ◽  
◽  
A.I. Popov ◽  
Keyword(s):  
Giant Magnetoresistance ◽  
Spin Valve ◽  
Random Access ◽  
Cmos Technology ◽  
Work Conditions ◽  
Spin Transfer ◽  
Boolean Logic ◽  
Spin Valves ◽  
Computing Systems ◽  
Technology Scaling

The base element of micromagnetic devices are the layered spin-valve structures. Small sizes, compatibility with the CMOS technology, scaling ability and various work conditions make the spin-valve structures a universal component of modern microelectronics. The purpose of present work is the analysis, systematization and generalization of the data of the work theoretical bases, experimental data and the application of spin valves. In the review, the hard disc drives, random-access magnetoresistive memory, the spin-transfer nano-oscillators, the magnetic biosensors, as well as various computing systems, operating on the principles of stochastic and deterministic logic, have been considered. The key theoretical works devoted to giant magnetoresistance and spin transfer have been used. The data on various types of the hard-disc readheads have been systematized, their architecture and parameters have been compared, and it has been shown how modern scientific research of nanomagnetic phenomena accelerates the growth rate of the recording density. The analysis of modern research devoted to magnetoresistive random access memory has been carried out. The problems of energy efficiency and increasing the degree of the integration for these devices have been discussed. The latest achievements in the field of materials, geometry and the properties of the spin-transfer nano-oscillators, as well as the problems and prospects for the development of this technology have been considered. The analysis of theoretical and experimental works, in which the spin-gate structures have been used to perform the logical operations of Boolean and non-Boolean logic, has been carried out. It has been shown how the probabilistic nature of the unstable switching of spin gates is used in the op-eration of the unconventional computing systems, namely, neuromorphic or Bayesian networks. The principles of operation of the spin valves as magnetic biosensors have been considered and the advantages of their application have been discussed.

scholarly journals EFFECT OF IMPURITIES AND EFFECTIVE MASSES ON SPIN-DEPENDENT ELECTRICAL TRANSPORT IN FERROMAGNET-NORMAL METAL-FERROMAGNET HYBRID JUNCTIONS

2002 ◽  
Vol 16 (19) ◽  
pp. 2857-2873 ◽  
Author(s):  
ZHEN-GANG ZHU ◽  
GANG SU ◽  
BIAO JIN ◽  
QING-RONG ZHENG
Keyword(s):  
Electrical Transport ◽  
Spin Valve ◽  
Normal Metal ◽  
Band Model ◽  
Effective Masses ◽  
Ferromagnetic Electrodes ◽  
Nonmagnetic Impurities ◽  
Spin Dependent Transport ◽  
Effect Of Impurities ◽  
Dependent Transport

The effect of nonmagnetic impurities and the effective masses on the spin-dependent transport in a ferromagnet-normal metal-ferromagnet junction is investigated on the basis of a two-band model. Our results show that impurities and the effective masses of electrons in two ferromagnetic electrodes have remarkable effects on the behaviors of the conductance, namely, both affect the oscillating amplitudes, periods, as well as the positions of the resonant peaks of the conductance considerably. The impurity tends to suppress the amplitudes of the conductance, and makes the spin-valve effect less obvious, but under certain conditions the phenomenon of the so-called impurity-induced resonant tunneling is clearly observed. The impurity and the effective mass both can lead to nonmonotonous oscillation of the junction magnetoresistance (JMR) with the incident energy and the thickness of the normal metal. It is also observed that a smaller difference of the effective masses of electrons in two ferromagnetic electrodes would give rise to a larger amplitude of the JMR.

scholarly journals Modeling of GMR loops asymmetry in spin valves

2018 ◽  
Vol 185 ◽  
pp. 01011
Author(s):  
Alexander Kurenkov ◽  
Georgy Babaizev ◽  
Nikolay Chechenin
Keyword(s):  
Magnetic Field ◽  
Simple Technique ◽  
Spin Valve ◽  
Hysteresis Loops ◽  
Spin Valves ◽  
Physical Factors ◽  
Regular Shape ◽  
Ferromagnetic Layers ◽  
Insight Into ◽  
Selection Of

The regular shape of the magnetoresistance as a function of applied magnetic field, R(H), is important for numerous spin valves applications. Nevertheless, in many practical studies the shape of the R(H) curve is unpredictably complicated. A simple technique, proposed in this paper, allows interpreting the R(H) features and calculating R(H) curves from known hysteresis loops of ferromagnetic layers, composing spin valves. And vice versa, the shape of the hysteresis loops of the composing ferromagnetic layers can be obtained from R(H) curves.The method does not give an insight into the physical factors determining the shape of hysteresis loops, but it is suitable for prompt selection of promising spin valve stacks. A series of spin valve structures was prepared and their magnetoresistance curves were measured. The analysis of the experimental data demonstrates the capacity of the proposed method.

MAGNETORESISTANCE IN NANO-SCALE NiO-CONTAINING Co/Cu/Co SPIN VALVES

2005 ◽  
Vol 19 (15n17) ◽  
pp. 2574-2579 ◽  
Author(s):  
A. M. ZHANG ◽  
X. S. WU ◽  
L. SUN ◽  
A. HU
Keyword(s):  
Room Temperature ◽  
Annealing Temperature ◽  
Growth Parameters ◽  
Coupling Effect ◽  
Spin Valve ◽  
Interface Roughness ◽  
Spin Valves ◽  
X Ray ◽  
X Ray Scattering

A series of NiO -containing Co/Cu/Co spin valves with the thickness Co of 5 nm and Cu of 2 nm were fabricated by magnetron sputtering technique with different growth parameters. NiO layer with the thickness of 40 nm is used as a coupling layer. Magnetoresistance (MR) of the spin valve with NiO layer under the bottom of Co/Cu/Co (BSV) is larger than that of the spin valve with NiO layer at the top of Co/Cu/Co (TSV) at room temperature. The MR values can be improved with decreasing the sputtering rate of copper layer. The studies by in-situ grazing incident X-ray scattering on the annealing temperature dependence of MR show that the decrease of the interface roughness between Co and NiO may increase the MR value, while the decrease of the coupling effect between NiO and Co decreases the MR value.

scholarly journals Penetration of a Magnetic Wall into Thin Ferromagnetic Electrodes of a Nano-Contact Spin Valve

2013 ◽  
Vol 82 (7) ◽  
pp. 074716
Author(s):  
Munetaka Sasaki ◽  
Susumu Tanaka ◽  
Yousuke Norizuki ◽  
Katsuyoshi Matsushita ◽  
Jun Sato ◽  
...  
Keyword(s):  
Spin Valve ◽  
Magnetic Wall ◽  
Ferromagnetic Electrodes

DEPENDENCE OF GIANT MAGNETORESISTANCE ON THE THICKNESS OF MAGNETIC AND NON-MAGNETIC LAYERS IN DUAL SPIN VALVES

2004 ◽  
Vol 18 (09) ◽  
pp. 355-365 ◽  
Author(s):  
YONG WANG ◽  
MING XU ◽  
ZHENHONG MAI
Keyword(s):  
Giant Magnetoresistance ◽  
Classical Model ◽  
Spin Valve ◽  
Magnetic Layer ◽  
Spin Valves ◽  
Experimental Result ◽  
Magnetic Layers ◽  
Ferromagnetic Layers ◽  
Hole Effect ◽  
Good Agreement

Based on the previous semi-classical model, we have performed calculation of the giant magnetoresistance (GMR) as a function of the thickness of the top/bottom or center ferromagnetic layers and the non-magnetic layer in dual spin valves. Our results are in good agreement with that reported in experiment, i.e., a GMR maximum is observed when the thickness of the top/bottom magnetic layer is at 20 ~ 40 Å; the GMR value decreases monotonically with the increase of the non-magnetic layer thickness. By considering the "pin-hole" effect, the variation of GMR versus the thickness of the center magnetic layer is also found to be consistent with the experimental result. These calculations will be helpful in the design of high-quality spin-valve structures.

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