scholarly journals Information storage in permalloy modulated magnetic nanowires

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guidobeth Sáez ◽  
Pablo Díaz ◽  
Eduardo Cisternas ◽  
Eugenio E. Vogel ◽  
Juan Escrig
Keyword(s):  
Magnetic Material ◽  
Phase Diagram ◽  
Magnetic Fields ◽  
Domain Walls ◽  
Wire Diameter ◽  
Information Storage ◽  
Magnetic Nanowires ◽  
The Wire ◽  
The Stability ◽  
Cylindrical Wire

AbstractA long piece of magnetic material shaped as a central cylindrical wire (diameter $$d=50$$ d = 50 nm) with two wider coaxial cylindrical portions (diameter $$D=90$$ D = 90 nm and thickness $$t=100$$ t = 100 nm) defines a bimodulated nanowire. Micromagnetism is invoked to study the equilibrium energy of the system under the variations of the positions of the modulations along the wire. The system can be thought of as composed of five independent elements (3 segments and 2 modulations) leading to $$2^5=32$$ 2 5 = 32 possible different magnetic configurations, which will be later simplified to 4. We investigate the stability of the configurations depending on the positions of the modulations. The relative chirality of the modulations has negligible contributions to the energy and they have no effect on the stability of the stored configuration. However, the modulations are extremely important in pinning the domain walls that lead to consider each segment as independent from the rest. A phase diagram reporting the stability of the inscribed magnetic configurations is produced. The stability of the system was then tested under the action of external magnetic fields and it was found that more than 50 mT are necessary to alter the inscribed information. The main purpose of this paper is to find whether a prototype like this can be complemented to be used as a magnetic key or to store information in the form of firmware. Present results indicate that both possibilities are feasible.

scholarly journals Information storage in permalloy modulated magnetic nanowires

2021 ◽  
Author(s):  
Guidobeth Sáez ◽  
Pablo Díaz ◽  
Eduardo Cisternas ◽  
Eugenio E. Vogel ◽  
Juan Escrig
Keyword(s):  
Magnetic Material ◽  
Phase Diagram ◽  
Magnetic Fields ◽  
Domain Walls ◽  
Wire Diameter ◽  
Information Storage ◽  
Magnetic Nanowires ◽  
The Wire ◽  
The Stability ◽  
Cylindrical Wire

Abstract A long piece of magnetic material shaped as a central cylindrical wire (diameter d = 50 nm) with two wider coaxial cylindrical portions (diameter D = 90 nm and thickness t = 100 nm) defines a bimodulated nanowire. Micromagnetism is invoked to study the equilibrium energy of the system under the variations of the positions of the modulations along the wire. The system can be thought of as composed of 5 independent elements (3 segments and 2 modulations) leading to 25 = 32 different magnetic configurations. We investigate the stability of the configurations depending on the positions of the modulations. The relative chirality of the modulations has negligible contributions to the energy and they have no effect in the stability of the stored configuration. However, the modulations are extremely important in pinning the domain walls that lead to consider each segment as independent from the rest. A phase diagram reporting the stability of the inscribed magnetic configurations is produced. The stability of the system was then tested under the action of external magnetic fields and it is found that more than 50 mT are necessary to alter the inscribed information. The main purpose of this paper is to find weather a prototype like this can complemented to be used as firmware or magnetic keys. Present results indicate that this is feasible.

Effect of the Wire Diameter on the Stability of Micro-Scale Ag/AgCl Reference Electrode

2017 ◽  
Vol 164 (14) ◽  
pp. E560-E564 ◽  
Author(s):  
S. Seghir Mechaour ◽  
A. Derardja ◽  
K. Oulmi ◽  
M. J. Deen
Keyword(s):  
Reference Electrode ◽  
Wire Diameter ◽  
Micro Scale ◽  
The Wire ◽  
The Stability

Nucleati on on domain walls near singular phase diagram points

1990 ◽  
Vol 111 (1) ◽  
pp. 111-115 ◽  
Author(s):  
A. A. Bulbich ◽  
P. E. Pumpjan
Keyword(s):  
Phase Diagram ◽  
Domain Walls

scholarly journals Magnetic Configurations in Modulated Cylindrical Nanowires

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 600
Author(s):  
Cristina Bran ◽  
Jose Angel Fernandez-Roldan ◽  
Rafael P. del Real ◽  
Agustina Asenjo ◽  
Oksana Chubykalo-Fesenko ◽  
...  
Keyword(s):  
Domain Walls ◽  
Magnetocrystalline Anisotropy ◽  
Logic Gates ◽  
Local Domain ◽  
Magnetic Nanowires ◽  
Precise Control ◽  
Magnetic Layers ◽  
State Present ◽  
Circular Domains ◽  
3D Applications

Cylindrical magnetic nanowires show great potential for 3D applications such as magnetic recording, shift registers, and logic gates, as well as in sensing architectures or biomedicine. Their cylindrical geometry leads to interesting properties of the local domain structure, leading to multifunctional responses to magnetic fields and electric currents, mechanical stresses, or thermal gradients. This review article is summarizing the work carried out in our group on the fabrication and magnetic characterization of cylindrical magnetic nanowires with modulated geometry and anisotropy. The nanowires are prepared by electrochemical methods allowing the fabrication of magnetic nanowires with precise control over geometry, morphology, and composition. Different routes to control the magnetization configuration and its dynamics through the geometry and magnetocrystalline anisotropy are presented. The diameter modulations change the typical single domain state present in cubic nanowires, providing the possibility to confine or pin circular domains or domain walls in each segment. The control and stabilization of domains and domain walls in cylindrical wires have been achieved in multisegmented structures by alternating magnetic segments of different magnetic properties (producing alternative anisotropy) or with non-magnetic layers. The results point out the relevance of the geometry and magnetocrystalline anisotropy to promote the occurrence of stable magnetochiral structures and provide further information for the design of cylindrical nanowires for multiple applications.

scholarly journals Giant conductivity of mobile non-oxide domain walls

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
S. Ghara ◽  
K. Geirhos ◽  
L. Kuerten ◽  
P. Lunkenheimer ◽  
V. Tsurkan ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Domain Wall ◽  
Domain Walls ◽  
Building Blocks ◽  
External Fields ◽  
Tail Domain ◽  
Oxide Electronics ◽  
Domain Wall Mobility ◽  
Conductance Changes ◽  
Wall Mobility

AbstractAtomically sharp domain walls in ferroelectrics are considered as an ideal platform to realize easy-to-reconfigure nanoelectronic building blocks, created, manipulated and erased by external fields. However, conductive domain walls have been exclusively observed in oxides, where domain wall mobility and conductivity is largely influenced by stoichiometry and defects. Here, we report on giant conductivity of domain walls in the non-oxide ferroelectric GaV4S8. We observe conductive domain walls forming in zig-zagging structures, that are composed of head-to-head and tail-to-tail domain wall segments alternating on the nanoscale. Remarkably, both types of segments possess high conductivity, unimaginable in oxide ferroelectrics. These effectively 2D domain walls, dominating the 3D conductance, can be mobilized by magnetic fields, triggering abrupt conductance changes as large as eight orders of magnitude. These unique properties demonstrate that non-oxide ferroelectrics can be the source of novel phenomena beyond the realm of oxide electronics.

scholarly journals The stability and electronic and photocatalytic properties of the ZnWO4 (010) surface determined from first-principles and thermodynamic calculations

RSC Advances ◽  
2021 ◽  
Vol 11 (38) ◽  
pp. 23477-23490
Author(s):  
Yonggang Wu ◽  
Jihua Zhang ◽  
Bingwei Long ◽  
Hong Zhang
Keyword(s):  
Phase Diagram ◽  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Thermodynamic Calculations ◽  
Photocatalytic Properties ◽  
Thermodynamic Approach ◽  
Functional Theory ◽  
Stability Phase Diagram ◽  
The Stability

The ZnWO4 (010) surface termination stability is studied using a density functional theory-based thermodynamic approach. The stability phase diagram shows that O-Zn, DL-W, and DL-Zn terminations of ZnWO4 (010) can be stabilized.

scholarly journals No-z Model for Magnetic Fields of Different Astrophysical Objects and Stability of the Solutions

Data ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 4
Author(s):  
Evgeny Mikhailov ◽  
Daniela Boneva ◽  
Maria Pashentseva
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Large Scale ◽  
Point Of View ◽  
Accretion Discs ◽  
Wide Range ◽  
Astrophysical Objects ◽  
Alpha Effect ◽  
The Stability ◽  
The Magnetic Field

A wide range of astrophysical objects, such as the Sun, galaxies, stars, planets, accretion discs etc., have large-scale magnetic fields. Their generation is often based on the dynamo mechanism, which is connected with joint action of the alpha-effect and differential rotation. They compete with the turbulent diffusion. If the dynamo is intensive enough, the magnetic field grows, else it decays. The magnetic field evolution is described by Steenbeck—Krause—Raedler equations, which are quite difficult to be solved. So, for different objects, specific two-dimensional models are used. As for thin discs (this shape corresponds to galaxies and accretion discs), usually, no-z approximation is used. Some of the partial derivatives are changed by the algebraic expressions, and the solenoidality condition is taken into account as well. The field generation is restricted by the equipartition value and saturates if the field becomes comparable with it. From the point of view of mathematical physics, they can be characterized as stable points of the equations. The field can come to these values monotonously or have oscillations. It depends on the type of the stability of these points, whether it is a node or focus. Here, we study the stability of such points and give examples for astrophysical applications.

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