scholarly journals Critical switching characteristics of three-layered spin valve for different materials and alloys with uniaxial anisotropy

2018 ◽  
Vol 185 ◽  
pp. 01012
Author(s):  
Iuliia Iusipova
Keyword(s):  
Spin Valve ◽  
Uniaxial Anisotropy ◽  
Magnetization Vector ◽  
Time Switching ◽  
Magnetic Parameters ◽  
Ferromagnetic Layers ◽  
Cobalt Iron ◽  
Critical Characteristics ◽  
Switching Characteristics ◽  
Layered Spin

We analyze the dependence of the current density and magnetic field switching on the magnetic parameters of the material of the ferromagnetic layers of the spin valve. Comparison of critical characteristics of the spin valve with longitudinal anisotropy of ferromagnetic layers fabricared of different materials showed that the promising materials for the fabrication of spin valve are cobalt, iron, their alloys, ferroborates of cobalt and alloys of cobalt with gadolinium. For these materials we produced and analyzed the bifurcation diagrams of equations describing the switching process of the spin valve. Based on the study of the dynamics of the magnetization vector we obtained the numerical evaluation of time switching.

scholarly journals Частота и быстродействие спинового вентиля с планарной анизотропией слоев

2020 ◽  
Vol 62 (9) ◽  
pp. 1361
Author(s):  
Ю.А. Юсипова
Keyword(s):  
Spin Valve ◽  
Practical Interest ◽  
Magnetization Vector ◽  
Magnetization Dynamics ◽  
Operating Modes ◽  
Read Head ◽  
Ferromagnetic Layers ◽  
Valve Structure ◽  
Switching Characteristics ◽  
Layered Spin

The dynamics of the magnetization vector in the free layer of a layered spin-valve structure was simulated. As materials for the free and fixed layers, six magnetically soft ferromagnets with longitudinal anisotropy were considered. The types of magnetization dynamics that are of practical interest for MRAM and HMDD (switching of the magnetization vector), STNO (stable precession of the magnetization vector), and the base element PSL (switching of the magnetization vector with two probable outcomes) were highlighted. The ranges of currents and fields corresponding to these operating modes of the spin valve were calculated. The numerical calculations of the switching time showed that, among the considered materials for the MRAM cell, the most suitable is Co80Gd20 alloy, while for the HMDD read head, it is Fe60Co20B20. As a result of the precession frequency calculations, it was concluded that the Fe60Co20B20 alloy is optimal for the STNO ferromagnetic layers. For the implementation of PSL, the best switching characteristics were demonstrated by the Co93Gd7 alloy.

Multiple Reflection Effect on Spin-Transfer Torque Dynamics in Spin Valves with a Single or Dual Polarizer

SPIN ◽  
2015 ◽  
Vol 05 (01) ◽  
pp. 1550003 ◽  
Author(s):  
Weiwei Zhu ◽  
Zongzhi Zhang ◽  
Jianwei Zhang ◽  
Yaowen Liu
Keyword(s):  
Spin Valve ◽  
Spin Transfer Torque ◽  
Multiple Reflection ◽  
Spin Transfer ◽  
Reflection Effect ◽  
Multiple Reflections ◽  
Applied Current ◽  
Negative Current ◽  
Ferromagnetic Layers ◽  
Scattering Matrix Method

In this paper, spin-dependent multiple reflection effect on spin-transfer torque (STT) has been theoretically and numerically studied in a spin valve nanopillar with a single or dual spin-polarizer. By using a scattering matrix method, we formulate an analytical expression of STT that contains the multiple interfacial reflection effect. It is found that the multiple reflections could enhance the STT efficiency and reduce the critical switching current. The STT efficiency depends on the spin polarization of both the free layer and polarizer. In the nanopillars with a dual spin polarizer, the multiple reflections would cause an asymmetric frequency dependence on the applied current, albeit exactly the same parameters are used in all three ferromagnetic layers, indicating that the frequency in the negative current varies much faster than that in the positive case.

Interfacial Contributions to Magnetostriction of Ferromagnetic Layers for Magnetoresistive Sensors

2002 ◽  
Vol 721 ◽  
Author(s):  
E.W. Singleton ◽  
K.J. Duxstad
Keyword(s):  
Layer Thickness ◽  
Spin Valve ◽  
Magnetic Layer ◽  
Experimental Results ◽  
Ferromagnetic Layers ◽  
Magnetoresistive Sensors

AbstractWe have experimentally measured magnetostriction of thin CoFe layers when deposited with various seed and capping layers. Seed and capping layers were chosen to be materials that may be used in spin-valve (SV) type structures. Materials deposited adjacent to the magnetic layer include Cu, Ta and TaN. The experimental results are interpreted using a model that allows separation of bulk and interface contributions to the measured magnetostriction [1].Results show a clear interfacial contribution that is dependent upon the material at the interface of the magnetic layer. The results demonstrate that surface contributions to the magnetostriction dominate as layer thickness decreases.

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.

Layer selective determination of magnetization vector configurations in an epitaxial double spin valve structure: Si(001)/Cu/Co/Cu/FeNi/Cu/Co/Cu

2000 ◽  
Vol 77 (6) ◽  
pp. 892-894 ◽  
Author(s):  
B. C. Choi ◽  
A. Samad ◽  
C. A. F. Vaz ◽  
J. A. C. Bland ◽  
S. Langridge ◽  
...  
Keyword(s):  
Spin Valve ◽  
Magnetization Vector ◽  
Selective Determination ◽  
Double Spin ◽  
Valve Structure

scholarly journals Магнитные фазы и неоднородные микромагнитные структуры в феррит-гранатовой пленке с ориентацией (210)

2018 ◽  
Vol 60 (5) ◽  
pp. 923
Author(s):  
Р.М. Вахитов ◽  
Р.Р. Исхакова ◽  
А.Р. Юмагузин
Keyword(s):  
Phase Diagram ◽  
Phase Transitions ◽  
Uniaxial Anisotropy ◽  
Magnetization Vector ◽  
Magnetic Phases ◽  
Common Structure ◽  
Magnetic Inhomogeneities ◽  
Domain Boundaries ◽  
Magnetic States

AbstractPossible magnetic states of a cubic ferromagnet with a uniaxial anisotropy induced along the [210] direction are theoretically investigated. It is demonstrated that the orientation phase diagram of a magnet is nontrivial and admits the existence of three types of magnetic phases that differ in transformational properties and the presence of quintuple points, isostructural phase transitions, etc. It is found that magnetic inhomogeneities, regardless of the values of parameters of the matter, have a common structure: they correspond to 180-degree domain boundaries with a noncircular trajectory of the magnetization vector. The features of homogeneous and inhomogeneous magnetic states, found in these materials, make it possible to explain the manifestation of a flexomagnetoelectric effect in them.

Fabrication Of La0.7Sr0.3MnO3/La0.5Sr0.5CoO3/La0.7Sr0.3MnO3 Heterostructures for Spin Valve Applications

1997 ◽  
Vol 494 ◽  
Author(s):  
M. C. Robson ◽  
S. B. Ogale ◽  
R. Godfrey ◽  
T. Venkatesan ◽  
M. Johnson ◽  
...  
Keyword(s):  
Hysteresis Loop ◽  
Spin Valve ◽  
Ferromagnetic Material ◽  
Perovskite Oxide ◽  
Structural Quality ◽  
X Ray Diffraction ◽  
Metallic Oxide ◽  
Ferromagnetic Layers ◽  
Double Hysteresis Loop

ABSTRACTEpitaxial growth of oxide heterostructures, which may be utilized in spin valve applications, has been demonstrated. The heterostructures consist of two ferromagnetic layers separated by a nonmagnetic metallic interlayer. The ferromagnetic material used is the manganese perovskite oxide, La0.7Sr0.3MnO3, while the metallic oxide interlayer is La0.5Sr0.5CoO3. X-ray diffraction spectra demonstrate the high structural quality of the heterostructures. The magnetization of the heterostructure as a function of magnetic field measured at room temperature yields a double hysteresis loop that is characteristic of this type of spin valve structure. The behavior of this double hysteresis loop is also examined as a function of the metallic interlayer thickness.

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.

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