scholarly journals Memristive Behavior in Magnetic Elements Separated by Thin Non-Magnetic Spacer Layer

2019 ◽  
Vol 8 (4) ◽  
pp. 2803-2806
Keyword(s):  
Domain Wall ◽  
Spin Polarization ◽  
Magnetic Moments ◽  
Magnetic Domains ◽  
Memristive Behavior ◽  
Magnetic Elements ◽  
Analytical Simulation ◽  
Spacer Layer ◽  
Spin Polarized ◽  
Pinched Hysteresis Loop

Memristance due to domain wall displacement following spin polarization of current through two magnetic elements with a thin non-magnetic spacer layer in between has been studied in this paper. A domain wall is a type of spin structure appearing between two magnetic domains. When spin polarized current interacts with the second layer it produces a change of resistance which depends on the relative orientation of the magnetic moments in layers. Analytical simulation results on 10 nm sample size domain wall have been obtained under the impression of magnetic field and spin polarization of current. The non-linear pinched hysteresis loop obtained as currentvoltage characteristics shows linearity at high frequencies.

scholarly journals Interaction of magnetic elements in metallic ferromagnetic nanofilms

2018 ◽  
Vol 185 ◽  
pp. 04006
Author(s):  
Panaetov V. P
Keyword(s):  
Comparative Analysis ◽  
Domain Wall ◽  
Domain Structure ◽  
Domain Walls ◽  
Magnetic Moments ◽  
Terminal Part ◽  
Noticeable Effect ◽  
Storage Devices ◽  
Magnetic Elements

In this paper, a comparative analysis of the distances between magnetic elements is made, under which a noticeable effect arises when they interact. The sides of the domain (domain walls), the terminal part of the domain (domain apex), we called magnetic elements. During magnetization, the domain structure is restructured. The distances between the domain walls, between the domain wall and domain apex, between the apexes of the domains change. A metallic ferromagnetic nanofilm can be a medium for recording information with the help of magnetic moments of electrons. Interaction of domain walls, the interaction of the domain wall and the domain apex, the interaction of the domain apexes in the design of storage devices must be taken into account.

Spin-Polarized Currents Induced by Multichannel Magnetic Point Contacts

SPIN ◽  
2019 ◽  
Vol 09 (03) ◽  
pp. 1950020
Author(s):  
Vahid Fallahi ◽  
Akbar Nazari-Golshan
Keyword(s):  
Domain Wall ◽  
Spin Polarization ◽  
Point Contact ◽  
Neumann Boundary ◽  
Coherent Scattering ◽  
Wall Structure ◽  
Magnetization Direction ◽  
Wall Width ◽  
Spin Polarized ◽  
Dependent Potential

We consider theoretically the spin blockade effect on the spin polarization of a current passing through a geometrically confined head-to-head 180∘ domain wall at a magnetic point contact in a two-dimensional (2D) metallic nanowire. The analysis is based on coherent scattering of the carriers by spin-dependent potential associated with the wall structure. The transmission properties of coherent states are obtained by introducing an algorithm to solve the coupled spin channels Schrödinger equation with mixed Dirichlet–Neumann boundary conditions applied far from the domain wall. It has been shown that a domain wall separating two media of opposite magnetization direction can act as a spin filter, allowing controllable modification of the spin polarization via the wall width.

Dynamical Nuclear Polarization

2018 ◽  
Author(s):  
M. M. Glazov
Keyword(s):  
Spin Polarization ◽  
Nuclear Spin ◽  
Nuclear Polarization ◽  
Magnetic Moments ◽  
Nonlinear Effects ◽  
Many Body ◽  
Nuclear Spin Polarization ◽  
Optical Resonances ◽  
Dynamical Nuclear Polarization ◽  
Temperature Concept

The transfer of nonequilibrium spin polarization between the electron and nuclear subsystems is studied in detail. Usually, a thermal orientation of nuclei in magnetic field is negligible due to their small magnetic moments, but if electron spins are optically oriented, efficient nuclear spin polarization can occur. The microscopic approach to the dynamical nuclear polarization effect based on the kinetic equation method, along with a phenomenological but very powerful description of dynamical nuclear polarization in terms of the nuclear spin temperature concept is given. In this way, one can account for the interaction between neighbouring nuclei without solving a complex many-body problem. The hyperfine interaction also induces the feedback of polarized nuclei on the electron spin system giving rise to a number of nonlinear effects: bistability of nuclear spin polarization and anomalous Hanle effect, dragging and locking of optical resonances in quantum dots. Theory is illustrated by experimental data on dynamical nuclear polarization.

scholarly journals Domain wall induced spin-polarized flat bands in antiferromagnetic topological insulators

2021 ◽  
Vol 103 (23) ◽  
Author(s):  
E. K. Petrov ◽  
V. N. Men'shov ◽  
I. P. Rusinov ◽  
M. Hoffmann ◽  
A. Ernst ◽  
...  
Keyword(s):  
Domain Wall ◽  
Topological Insulators ◽  
Flat Bands ◽  
Spin Polarized

Magnetic Properties of Embedded Rh Clusters in Ni Matrix

1995 ◽  
Vol 384 ◽  
Author(s):  
Zhi-Qiang Li ◽  
Yuichi Hashi ◽  
Jing-Zhi Yu ◽  
Kaoru Ohno ◽  
Yoshiyuki Kawazoe
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Magnetic Moments ◽  
Functional Formalism ◽  
Rhodium Clusters ◽  
Spin Polarized ◽  
Local Density Functional

ABSTRACTThe electronic structure and magnetic properties of rhodium clusters with sizes of 1 - 43 atoms embedded in the nickel host are studied by the first-principles spin-polarized calculations within the local density functional formalism. Single Rh atom in Ni matrix is found to have magnetic moment of 0.45μB. Rh13 and Rhl 9 clusters in Ni matrix have lower magnetic moments compared with the free ones. The most interesting finding is tha.t Rh43 cluster, which is bulk-like nonmagnetic in vacuum, becomes ferromagnetic when embedded in the nickel host.

Determination of Intrinsic Magnetic Parameters of SmCo5 Phase in Sintered Samples

2005 ◽  
Vol 498-499 ◽  
pp. 129-133 ◽  
Author(s):  
Marcos Flavio de Campos ◽  
Fernando José Gomes Landgraf
Keyword(s):  
Powder Metallurgy ◽  
Domain Wall ◽  
Kerr Effect ◽  
Critical Diameter ◽  
Optical Microscope ◽  
Domain Theory ◽  
Magnetic Domains ◽  
Magnetic Parameters ◽  
Intrinsic Parameters

SmCo5 magnets are usually produced by powder metallurgy route, including milling, compaction and orientation under magnetic field, sintering and heat treatment. The samples produced by powder metallurgy, with grain size around 10 μm, are ideal for determination of intrinsic parameters. The first step for determination of intrinsic magnetic parameters is obtaining images of domain structure in demagnetized samples. In the present study, the domain images were produced by means of Kerr effect, in a optical microscope. After the test of several etchings, Nital appears as the most appropriate for observation of magnetic domains by Kerr effect. Applying Stereology and Domain Theory, several intrinsic parameters of SmCo5 phase were determined: domain wall energy 120 erg/cm2, critical diameter for single domain particle size 2 μm and domain wall thickness 60 Å. In the case of SmCo5, and also other phases with high magnetocrystalline anisotropy, Domain Theory presents several advantages when compared with Micromagnetics.

Effects on the magnetic and optical properties of Co-doped ZnO at different electronic states

2017 ◽  
Vol 31 (31) ◽  
pp. 1750247
Author(s):  
Qingyu Huo ◽  
Zhenchao Xu ◽  
Linfeng Qu
Keyword(s):  
Absorption Spectrum ◽  
Spin Polarization ◽  
Electron Spin ◽  
Magnetic Moments ◽  
The State ◽  
Band Gaps ◽  
Electron Spin Polarization ◽  
Approximation Formula ◽  
Doped Zno ◽  
Co Doped

Both blue and red shifts in the absorption spectrum of Co-doped ZnO have been reported at a similar concentration range of doped Co. Moreover, the sources of magnetism of Co-doped ZnO are controversial. To solve these problems, the geometry optimization and energy of different Co-doped ZnO systems were calculated at the states of electron spin polarization and nonspin polarization by adopting plane-wave ultra-soft pseudopotential technology based on density function theory. At the state of electron nonspin polarization, the total energies increased as the concentration of Co-doped increased. The doped systems also became unstable. The formation energies increased and doping became difficult. Furthermore, the band gaps widened and the absorption spectrum exhibited a blue shift. The band gaps were corrected by local-density approximation + [Formula: see text] at the state of electron spin polarization. The magnetic moments of the doped systems weakened as the concentration of doped Co increased. The magnetic moments were derived from the coupling effects of [Formula: see text]–[Formula: see text]. The band gaps narrowed and the absorption spectrum exhibited a red shift. The inconsistencies of the band gaps and absorption spectrum at the states of electron spin polarization and nonspin polarization were first discovered in this research, and the sources of Co-doped ZnO magnetism were also reinterpreted.

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