Eﬀective modulation of spin accumulation using a ferromagnetic/nonmagnetic bilayer spin channel

Abstract A lateral spin valve consisting of highly spin-polarized CoFeAl electrodes with a CoFeAl/Cu bilayer spin channel has been developed. Despite a large spin absorption into the CoFeAl capping channel layer, an eﬃcient spin injection and detection using the CoFeAl electrodes enable us to observe a clear spin valve signal. We demonstrate that the nonlocal spin accumulation signal is signiﬁcantly modulated depending on the relative angle of the magnetizations between the spin injector and absorber. The observed modulation phenomena is explained by the longitudinal and transverse spin absorption eﬀects into the CoFeAl channel layer with the spin resistance model.

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Corrigendum: Large spin accumulation signal in half-metallic Co2MnSi based lateral spin valve devices

Journal of Physics D Applied Physics ◽

10.1088/0022-3727/46/38/389501 ◽

2013 ◽

Vol 46 (38) ◽

pp. 389501

Author(s):

Fujun Yang ◽

Zewei Kang ◽

Xiaoqin Chen ◽

Yun Xue

Keyword(s):

Spin Valve ◽

Spin Accumulation ◽

Half Metallic ◽

Large Spin

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Enhanced Spin Accumulation in Semiconductor at Room Temperature Using Ni0.65Zn0.35Fe2O4(NZFO) as Spin Injector in NZFO/MgO/p-Si Device

Frontiers in Materials ◽

10.3389/fmats.2021.721031 ◽

2021 ◽

Vol 8 ◽

Author(s):

Nilay Maji ◽

Subhasis Shit ◽

T. K. Nath

Keyword(s):

Room Temperature ◽

Spin Diffusion ◽

Diffusion Length ◽

Spin Injection ◽

Spin Accumulation ◽

Injection Model ◽

Tunnel Contact ◽

Current Voltage ◽

Spin Polarized ◽

Junction Structure

In this article, the fabrication of a Ni0.65Zn0.35Fe2O4/MgO/p-Si heterostructure device has been optimized using the pulsed laser deposition (PLD) technique, and a detailed investigation of its structural, electrical, and magnetic features has been performed experimentally. The electronic and magneto-transport characteristics have been explored in the temperature range of 100–300 K. The current-voltage (I-V) characteristics of the heterojunction have been recorded, which displayed an excellent rectifying magnetic tunnel diode-like behavior throughout that temperature regime. The application of an external magnetic field parallel to the plane of the NZFO film causes the current (I) across the junction to decrease, clearly indicating positive junction magnetoresistance (JMR) of the heterostructure. The root of displaying positive magnetoresistance in our heterojunction has been well justified using the standard spin injection model. The electrical injection of spin-polarized carriers and its accumulation and detection in a p-Si channel have been demonstrated using the NZFO/MgO tunnel contact using a three-terminal (3-T) Hanle device. The parameters such as spin lifetime (99 ps), spin diffusion length (276 nm), and spin polarization (0.44) have been estimated from the Hanle curve detected in our heterostructure at room temperature, making the Ni0.65Zn0.35Fe2O4/MgO/p-Si device a very favorable promising junction structure in the field of spintronics for several device appliances in the future.

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Large spin accumulation signal in half-metallic Co2MnSi based lateral spin valve devices

Journal of Physics D Applied Physics ◽

10.1088/0022-3727/46/32/325003 ◽

2013 ◽

Vol 46 (32) ◽

pp. 325003 ◽

Cited By ~ 2

Author(s):

Fujun Yang ◽

Zewei Kang ◽

Xiaoqin Chen ◽

Yun Xue

Keyword(s):

Spin Valve ◽

Spin Accumulation ◽

Half Metallic ◽

Large Spin

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COMPARATIVE STUDY OF SPIN INJECTION AND TRANSPORT IN Alq3 AND Co–PHTHALOCYANINE-BASED ORGANIC SPIN VALVES

SPIN ◽

10.1142/s2010324714400098 ◽

2014 ◽

Vol 04 (02) ◽

pp. 1440009 ◽

Cited By ~ 11

Author(s):

SAYANI MAJUMDAR ◽

SUKUMAR DEY ◽

HANNU HUHTINEN ◽

JOHNNY DAHL ◽

MARJUKKA TUOMINEN ◽

...

Keyword(s):

Single Molecule ◽

Giant Magnetoresistance ◽

Chemical Reactivity ◽

Spin Injection ◽

Spin Valve ◽

Spin Valves ◽

Half Metallic ◽

High Expectations ◽

Spacer Layer ◽

Spin Polarized

Recent experimental reports suggest the formation of a highly spin-polarized interface ("spinterface") between a ferromagnetic (FM) Cobalt ( Co ) electrode and a metal-phthalocyanine (Pc) molecule. Another report shows an almost 60% giant magnetoresistance (GMR) response measured on Co / H 2 Pc -based single molecule spin valves. In this paper, we compare the spin injection and transport properties of organic spin valves with two different organic spacers, namely Tris(8-hydroxyquinolinato) aluminum ( Alq 3) and CoPc sandwiched between half-metallic La 0.7 Sr 0.3 MnO 3 (LSMO) and Co electrodes. Alq 3-based spin valves exhibit clear and reproducible spin valve switching with almost 35% negative GMR at 10 K, in accordance with previous reports. In contrast, cobalt-pthalocyanine ( CoPc )-based spin valves fail to show clear GMR response above noise level despite high expectations based on recent reports. Investigations of electronic, magnetic and magnetotransport properties of electrode/spacer interfaces of LSMO/ CoPc / Co devices offer three plausible explanations for the absence of GMR: (1) CoPc films are strongly chemisorbed on the LSMO surface. This improves the LSMO magnetic properties but also induces local traps at the LSMO interface for spin-polarized charge carriers. (2) At the Co / CoPc interface, diffusion of Co atoms into the organic semiconductor (OS) layer and chemical reactivity between Co and the OS deteriorates the FM properties of Co . This renders the Co / CoPc interface as unsuitable for efficient spin injection. (3) The presence of heavy Co atoms in CoPc leads to large spin–orbit coupling in the spacer. The spin relaxation time in the CoPc layer is therefore considerably smaller compared to Alq 3. Based on these findings, we suggest that the absence of GMR in CoPc -based spin valves is caused by a combined effect of inefficient spin injection from FM contacts and poor spin transport in the CoPc spacer layer.

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JOINT ACTION OF SPIN-TRANSFER AND SPIN-INJECTION TORQUES IN FERROMAGNETIC JUNCTIONS

International Journal of Nanoscience ◽

10.1142/s0219581x0700495x ◽

2007 ◽

Vol 06 (05) ◽

pp. 363-366

Author(s):

ERNEST EPSHTEIN ◽

YURI GULYAEV ◽

PETER ZILBERMAN

Keyword(s):

Joint Action ◽

Spin Injection ◽

Spin Valve ◽

Spin Transfer ◽

Simultaneous Action ◽

Transverse Spin ◽

Spin Wave Excitations ◽

Instability Development ◽

First Time ◽

A Current

We consider theoretically a current flowing perpendicular to interfaces of a spin-valve type ferromagnetic metallic junction. For the first time a simultaneous action of the two current effects is investigated, namely, the nonequilibrium longitudinal spin injection and the transverse spin surface torque. Dispersion relations for fluctuations are derived and solved under the proper boundary conditions. Joint action of the two effects mentioned lowers the instability threshold, its typical value being 1 × 106–3 × 107 A/cm2. Spin wave excitations may soften near the threshold. A nonlinear problem is solved about steady state arising due to instability development.

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Nonlinear Damping Generated by Spin Injection in a Pseudo-spin-valve Structure

MRS Proceedings ◽

10.1557/proc-998-j02-04 ◽

2007 ◽

Vol 998 ◽

Author(s):

Min Ren ◽

Lei Zhang ◽

Jiuning Hu ◽

Ning Deng ◽

Hao Dong ◽

...

Keyword(s):

Spin Relaxation ◽

Spin Injection ◽

Magnetic Moments ◽

Spin Valve ◽

Nonlinear Damping ◽

Spin Transfer Torque ◽

Spin Transfer ◽

Spin Accumulation ◽

Magnetic Damping ◽

Magnetic Dynamic

ABSTRACTThe current induced magnetic dynamics of a nano-scale pseudo-spin-valve (PSV) structure was theoretically studied. The spin relaxation mechanisms and the influence of ferromagnetic/nonmagnetic (FM/NM) interfaces on the current polarization were investigated, and a modified magnetic dynamic equation was developed. Both the free layer's local magnetic moments and itinerant electrons' spins were regarded as a macro-spin, whose movement was resulted from two items: spin relaxation due to the magnetic damping and spin accumulation due to the polarized current. The injected current not only produces a spin transfer torque, but also alters the effective magnetic field, and thus affects the damping. Therefore, the damping is nonlinear and correlated to the current. Based on the analysis of the competition between magnetic damping and spin accumulation, the dynamic behaviors of magnetization switching and oscillation can be explained.

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Enhanced spin accumulation in nano-pillar-based lateral spin valve using spin reservoir effect

Journal of Physics D Applied Physics ◽

10.1088/1361-6463/ac47bf ◽

2022 ◽

Author(s):

Xiaomin Cui ◽

Shaojie Hu ◽

Takashi Kimura

Keyword(s):

Spin Diffusion ◽

Spin Injection ◽

Spin Valve ◽

Spin Current ◽

Spin Valves ◽

Pure Spin ◽

Spin Accumulation ◽

Spintronic Devices ◽

High Bias ◽

Angle Deposition

Abstract Lateral spin valves are ideal nanostructures for investigating spin-transport physics phenomena and promoting the development of future spintronic devices owing to dissipation-less pure spin current. The magnitude of the spin accumulation signal is well understood as a barometer for characterizing spin current devices. Here, we develop a novel fabrication method for lateral spin valves based on ferromagnetic nanopillar structures using a multi-angle deposition technique. We demonstrate that the spin-accumulation signal is effectively enhanced by reducing the lateral dimension of the nonmagnetic spin channel. The obtained results can be quantitatively explained by the confinement of the spin reservoir by considering spin diffusion into the leads. The temperature dependence of the spin accumulation signal and the influence of the thermal spin injection under a high bias current are also discussed.

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