Generation of magnetic skyrmions through pinning effect

Based on analytical estimation and lattice simulation, a proposal is made that magnetic skyrmions can be generated through the pinning effect in 2D chiral magnetic materials, in the absence of an external magnetic field or magnetic anisotropy. In our simulation, stable magnetic skyrmions can be generated in the pinning areas. The properties of the skyrmions are studied for various values of ferromagnetic exchange strength and the Dzyaloshinskii–Moriya interaction strength.

Download Full-text

Computer Simulation of Magnetic Skyrmions

Proceedings ◽

10.3390/ecea-5-06678 ◽

2019 ◽

Vol 46 (1) ◽

pp. 6

Author(s):

Vitalii Kapitan ◽

Egor Vasiliev ◽

Alexander Perzhu

Keyword(s):

Magnetic Field ◽

Numerical Simulation ◽

Computer Simulation ◽

External Magnetic Field ◽

Single Layer ◽

Metropolis Algorithm ◽

Square Lattice ◽

Temperature Behaviour ◽

Magnetic Skyrmions ◽

Moriya Interaction

In this paper, we present the results of a numerical simulation of thermodynamics for the array of Classical Heisenberg spins placed on a 2D square lattice, which effectively represents the behaviour of a single layer. Using the Metropolis algorithm, we show the temperature behaviour of the system with a competing Heisenberg and Dzyaloshinskii–Moriya interaction (DMI) in contrast with the classical Heisenberg system. We show the process of nucleation of the skyrmion depending on the value of the external magnetic field. We proposed the controlling method for the movement of skyrmions.

Download Full-text

Monte Carlo Simulation of Magnetic Skyrmions in Ferromagnetic Films

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.312.256 ◽

2020 ◽

Vol 312 ◽

pp. 256-260

Author(s):

Alexander Perzhu ◽

Egor Vasiliev ◽

Dmitrii Kapitan ◽

Roman Volotovskiy ◽

Alexey Rybin ◽

...

Keyword(s):

Magnetic Field ◽

Monte Carlo Simulation ◽

Monte Carlo ◽

External Magnetic Field ◽

Magnetic Films ◽

Magnetic Vortex ◽

Heisenberg Spin ◽

Monte Carlo Simulation Technique ◽

Magnetic Skyrmions ◽

Moriya Interaction

Magnetic films, in which magnetic vortex textures - skyrmions appear because of competition between the direct Heisenberg exchange and the Dzyaloshinskii-Moriya interaction, were studied using the Monte-Carlo simulation technique. The conditions for the nucleation and stable existence of magnetic skyrmions in magnetic films in the frame of the classical Heisenberg model were considered in the paper. The process of nucleation of skyrmions with increasing of the external magnetic field was studied, various phases into which the Heisenberg spin system passes were recognized. A phase diagram was plotted: it shows the behavior of the system at the constant value of temperature depending on values of an external magnetic field and Dzyaloshinskii-Moriya interaction.

Download Full-text

INFLUENCE OF AN EXTERNAL MAGNETIC FIELD ON THE DYNAMICS OF A NEW-PHASE NUCLEUS IN THE VICINITY OF THE FIRST-ORDER PHASE TRANSITION IN MAGNETS WITH DEFECTS PRESENT

Modern Physics Letters B ◽

10.1142/s0217984912501837 ◽

2012 ◽

Vol 26 (28) ◽

pp. 1250183 ◽

Cited By ~ 5

Author(s):

VLADIMIR NAZAROV ◽

RISHAT SHAFEEV

Keyword(s):

Magnetic Field ◽

Phase Transition ◽

External Magnetic Field ◽

Magnetic Anisotropy ◽

Spin Reorientation ◽

Critical Fields ◽

First Order ◽

Phase Nucleus ◽

First Order Phase Transition ◽

New Phase

Theoretically, with the aid of a soliton model, the evolution of a new-phase nucleus near the first-order spin-reorientation phase transition in magnets has been investigated in an external magnetic field. The influence of an external field and one-dimensional defects of magnetic anisotropy on the dynamics of such nucleus has been demonstrated. The conditions for the localization of the new-phase nucleus in the region of the magnetic anisotropy defect and for its escape from the defect have been determined. The values of the critical fields which bring about the sample magnetization reversal have been identified and estimated.

Download Full-text

High Frequency Magnetoimpedance of FeNi/Cu/FeNi Sensitive Elements with Different Geometries

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.152-153.373 ◽

2009 ◽

Vol 152-153 ◽

pp. 373-376 ◽

Cited By ~ 4

Author(s):

Stanislav O. Volchkov ◽

Andrey V. Svalov ◽

G.V. Kurlyandskaya

Keyword(s):

Magnetic Field ◽

Experimental Data ◽

External Magnetic Field ◽

Finite Elements ◽

Magnetic Anisotropy ◽

Constant Magnetic Field ◽

High Frequency ◽

Complex Impedance ◽

Rf Sputtering ◽

Frequency Range

In this work magnetoimpedance (MI) behaviour was studied experimentally for Fe19Ni81(175 nm)/Cu(350 nm)/Fe19Ni81(175 nm) sensitive elements deposited by rf-sputtering. A constant magnetic field was applied in plane of the sandwiches during deposition perpendicular to the Cu-lead in order to induce a magnetic anisotropy. Sandwiches with different width (w) of FeNi parts were obtained. The complex impedance was measured as a function of the external magnetic field for a frequency range of 1 MHz to 700 MHz for MI elements with different geometries. Some of MI experimental data are comparatively analysed with finite elements numerical calculations data. The obtained results can be useful for optimization of the design of miniaturized MI detectors.

Download Full-text

Unravelling the Anisotropic Behavior of Nickel—Wires Prepared through External Magnetic Field Assisted Hydrazine Reduction Method

Applied Sciences ◽

10.3390/app11188627 ◽

2021 ◽

Vol 11 (18) ◽

pp. 8627

Author(s):

Min-Soo Kim ◽

Min-Ji Shin ◽

Akshay Kumar ◽

Kavita Kumari ◽

Seok-Hwan Huh ◽

...

Keyword(s):

Magnetic Field ◽

External Magnetic Field ◽

Magnetic Anisotropy ◽

Saturation Magnetization ◽

Synthesis Method ◽

Ferromagnetic Behavior ◽

Geometrical Shape ◽

Face Centered Cubic ◽

Minimum Diameter ◽

Hydrazine Reduction

Ni wires, prepared through a hydrazine reduction, were exposed to external magnetic fields of different geometrical shape and configuration during the synthesis denoted as Ni-Non-Magnetic, Ni-Double, Ni-Single, Ni-Ring. Their effect on the wire morphology, magnetization and magnetic anisotropy was then investigated via various characterization techniques viz. X-ray diffraction (XRD), high-resolution field emission scanning electron microscopy (HR-FESEM), and vibrating sample magnetometer (VSM). The polycrystalline single phase of the Ni-wires with face centered cubic symmetry was confirmed through the analysis of XRD patterns. Analysis of HR-FESEM images revealed that the Ni-particles were aligned in form of wire-like morphology. The Ni-single sample formed the wires with minimum diameter compared to the parent sample. The magnetization measurements performed at 300 K and 50 K demonstrated the ferromagnetic behavior of all the samples. The room temperature saturation magnetization (MS) and anisotropy constant (K) of the Ni-wires were reduced upon providing the external field during synthesis. However, the low temperature (50 K) magnetization behavior was rather opposing, indicating enhanced values of MS and K. Among all, Ni-ring sample showed maximum anisotropy with a value of 3.84 × 104 erg/cm3 at 50 K. The ambiguous nature of the anisotropic constant and saturation magnetization ascribed partly to the variation in diameters of Ni-wires and to the intermittent spin-spin exchange interactions of unaligned/partially aligned particles during the synthesis. Briefly, in the present study, it was established that the morphology and magnetic anisotropy of the Ni-wires could be tailored through the external magnetic field assisted synthesis method.

Download Full-text

Magnetization and Curie Temperature of Ferromagnetic Ultrathin Films: The Influence of Magnetic Anisotropy and Dipolar Interactions (invited)

MRS Proceedings ◽

10.1557/proc-231-299 ◽

1991 ◽

Vol 231 ◽

Cited By ~ 19

Author(s):

P. Bruno

Keyword(s):

Magnetic Field ◽

External Magnetic Field ◽

Curie Temperature ◽

Magnetic Anisotropy ◽

Long Range ◽

Ultrathin Films ◽

Experimental Results ◽

Dipolar Interactions ◽

Surface Gradient ◽

Theoretical Investigations

AbstractTheoretical investigations of the magnetization and Curie temperature of ferromagnetic ultrathin films in the presence of magnetic anisotropy and long-range dipolar interactions are presented. The Curie temperature of fcc (001) cobalt ultrathin films is calculated and compared with experimental results on Co/Cu (001) films. The influence of an external magnetic field, and the surface gradient of the magnetization are also discussed.

Download Full-text

Quantum teleportation via two-qubit Heisenberg XYZ chain

Canadian Journal of Physics ◽

10.1139/cjp-2013-0404 ◽

2014 ◽

Vol 92 (5) ◽

pp. 406-410 ◽

Cited By ~ 4

Author(s):

Nour Zidan

Keyword(s):

Magnetic Field ◽

External Magnetic Field ◽

Quantum Teleportation ◽

Initial System ◽

Entangled State ◽

Initial State ◽

Intrinsic Decoherence ◽

Average Fidelity ◽

Moriya Interaction

Quantum teleportation via the entanglement channel composed of a two-qubit Heisenberg XYZ chain with Dzyaloshinskii–Moriya interaction in the presence of both inhomogeneous external magnetic field and intrinsic decoherence has been investigated. It is shown that the initial state of the channel plays an important role in the fully entangled fraction and the average fidelity of teleportation. It is found that when the initial system is in the entangled state |Ψ⟩ = m2|01⟩ + n2|10⟩ the corresponding average fidelity is always larger than 2/3.

Download Full-text

Magnetic alignment in 2212 Bi-based superconducting system: Part I. Magnetic orientation of Bi2Sr2Ca1−x(RE)xCu2O8−y [(RE) = Gd, Dy, Ho, Er] powder dispersed in epoxy resin at room temperature

Journal of Materials Research ◽

10.1557/jmr.1996.0137 ◽

1996 ◽

Vol 11 (5) ◽

pp. 1082-1085 ◽

Cited By ~ 16

Author(s):

S. Stassen ◽

R. Cloots ◽

Ph. Vanderbemden ◽

P. A. Godelaine ◽

H. Bougrine ◽

...

Keyword(s):

Magnetic Field ◽

Rare Earth ◽

External Magnetic Field ◽

Magnetic Anisotropy ◽

Epoxy Resin ◽

Room Temperature ◽

Magnetic Alignment ◽

Magnetic Orientation ◽

System Part ◽

The Rare Earth

The magnetic anisotropy of rare-earth substituted 2212 materials (Bi2Sr2Ca0.8RE0.2Cu2Ox with RE = Gd, Dy, Ho, Er) is put into evidence. Superconducting powder dispersed in epoxy resin is oriented under an external magnetic field (4 T) in a direction that depends on the nature of the rare-earth used in the substitution. Both directions of observation (parallel or perpendicular to the field) were investigated. Splitting of (00l) peaks is neatly observed and discussed.

Download Full-text