Reflection of spin waves from a ferromagnetic multilayer with interfacial coupling of finite strength (reflection of spin waves from multilayer)

Open Physics ◽  
2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Yuri Gorobets ◽  
Sergey Reshetnyak
Keyword(s):  
Magnetic Field ◽  
Reflection Coefficient ◽  
Magnetic Anisotropy ◽  
Saturation Magnetization ◽  
Exchange Interaction ◽  
Spin Waves ◽  
Interfacial Coupling ◽  
Bias Magnetic Field ◽  
Uniaxial Magnetic Anisotropy ◽  
Magnonic Crystal

AbstractThe reflection coefficient of bulk spin waves from a ferromagnetic multilayer with periodically modulated parameters of the exchange interaction, the uniaxial magnetic anisotropy and the saturation magnetization (a magnonic crystal) is calculated. The dependence of the reflection coefficient upon the spin wave frequency and the values of the bias magnetic field, the parameter of interfacial coupling, and the internal structure of the unit cell are investigated.

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

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.

Angular dependence of saturation magnetization in single crystals with uniaxial magnetic anisotropy

2021 ◽  
pp. 168947
Author(s):  
D.S. Neznakhin ◽  
A.S. Bolyachkin ◽  
M.I. Bartashevich ◽  
L.V.B. Diop ◽  
O. Gutfleisch ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Saturation Magnetization ◽  
Single Crystals ◽  
Angular Dependence ◽  
Uniaxial Magnetic Anisotropy

The loss of mechanical stability and the critical magnetization of a ferromagnetic particle in an elastomer

Soft Matter ◽  
2019 ◽  
Vol 15 (29) ◽  
pp. 5987-5994 ◽  
Author(s):  
V. M. Kalita ◽  
Yu. I. Dzhezherya ◽  
G. G. Levchenko
Keyword(s):  
Magnetic Field ◽  
Magnetic Anisotropy ◽  
Mechanical Stability ◽  
Ferromagnetic Particle ◽  
Uniaxial Magnetic Anisotropy ◽  
Soft Ferromagnetic

The loss of mechanical stability of a spherical magnetically soft ferromagnetic particle with uniaxial magnetic anisotropy and located in an elastomer under the action of a magnetic field has been studied theoretically.

Magnetoelectric Effect of the Ba0.80Sr0.2TiO3-CoFe2O4 Ceramic Composites by Molten-Salt Synthesis Method

2012 ◽  
Vol 268-270 ◽  
pp. 63-66
Author(s):  
Wei Rao ◽  
Ding Guo Li ◽  
Hong Chun Yan
Keyword(s):  
Magnetic Field ◽  
Particle Size ◽  
Molten Salt ◽  
Coupling Coefficient ◽  
Magnetoelectric Effect ◽  
Synthesis Method ◽  
Ceramic Composites ◽  
Molten Salt Synthesis ◽  
Interfacial Coupling ◽  
Bias Magnetic Field

This paper presents the structural, ferroelectric, ferromagnetic, resonance and magnetoelectric (ME) properties of multilayered ME composites fabricated using molten-salt synthesis method. The compositions corresponding to CoFe2O4 (CFO) with particle size of ~ 150 nm and Ba0.8Sr0.2TiO3 (BST) with particle size of ~ 100 nm were chosen as ferromagnetic and ferroelectric phases. The largest direct magnetoelectric (DME) and converse magnetoelectric (CME) coefficients of the multilayered ME composite were, respectively, 36 μV/cm•Oe at a bias magnetic field of 2800 Oe and 1.16×10-3G/V at a frequency of 30 kHz. In addition, the corresponding interfacial coupling coefficient was calculated to be 3.2×10-5. For the multilayered ME composite, the resonance frequency of 4.97 MHz and bandwidth of 30 kHz were obtained using capacitance-frequency spectrum method.

scholarly journals Small-angle neutron scattering correlation functions of bulk magnetic materials

2015 ◽  
Vol 48 (5) ◽  
pp. 1437-1450 ◽  
Author(s):  
Denis Mettus ◽  
Andreas Michels
Keyword(s):  
Magnetic Field ◽  
Correlation Function ◽  
Magnetic Anisotropy ◽  
Neutron Scattering ◽  
Saturation Magnetization ◽  
Applied Magnetic Field ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Anisotropy Field ◽  
Two Dimensional

On the basis of the continuum theory of micromagnetics, the correlation function of the spin-misalignment small-angle neutron scattering cross section of bulk ferromagnets (e.g.elemental polycrystalline ferromagnets, soft and hard magnetic nanocomposites, nanoporous ferromagnets, or magnetic steels) is computed. For such materials, the spin disorder which is related to spatial variations in the saturation magnetization and magnetic anisotropy field results in strong spin-misalignment scattering dΣM/dΩ along the forward direction. When the applied magnetic field is perpendicular to the incoming neutron beam, the characteristics of dΣM/dΩ (e.g.the angular anisotropy on a two-dimensional detector or the asymptotic power-law exponent) are determined by the ratio of magnetic anisotropy field strengthHpto the jump ΔMin the saturation magnetization at internal interfaces. Here, the corresponding one- and two-dimensional real-space correlations are analyzed as a function of applied magnetic field, the ratioHp/ΔM, the single-particle form factor and the particle volume fraction. Finally, the theoretical results for the correlation function are compared with experimental data on nanocrystalline cobalt and nickel.

Uniaxial magnetic anisotropy of amorphous Fe–B films deposited electrochemically in a magnetic field

1999 ◽  
Vol 85 (8) ◽  
pp. 4503-4505 ◽  
Author(s):  
Naoyuki Fujita ◽  
Mitsuteru Inoue ◽  
Ken’Ichi Arai ◽  
Masanobu Izaki ◽  
Toshitaka Fujii
Keyword(s):  
Magnetic Field ◽  
Magnetic Anisotropy ◽  
Uniaxial Magnetic Anisotropy
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