Ferromagnetic resonance spectra of linear magnetosome chains

• Elizaveta M. Gubanova and
• Nikolai A. Usov

Beilstein J. Nanotechnol. 2024, 15, 157–167, doi:10.3762/bjnano.15.15

• chain, the distance between the centers of neighboring particles, the mutual orientation of the cubic axes of particle anisotropy, and the value of the magnetic damping constant is studied. It is shown that FMR spectra of non-oriented chain assemblies depend on the average particle diameter at a fixed

• thickness of the lipid magnetosome membrane, as well as on the value of the magnetic damping constant. At the same time, they are practically independent of the number Np of particles in the chain under the condition Np ≥ 10. The FMR spectra of non-oriented assemblies of magnetosome chains are compared with

• of the i-th single-domain nanoparticle of the chain is governed by the stochastic Landau–Lifshitz equation [29][30][31][32], where γ is the gyromagnetic ratio, γ1 = γ/(1 + κ2), κ is the magnetic damping constant, is the effective magnetic field, and is the thermal field. The effective magnetic

Dynamics of superparamagnetic nanoparticles in viscous liquids in rotating magnetic fields

• Nikolai A. Usov,
• Ruslan A. Rytov and
• Vasiliy A. Bautin

Beilstein J. Nanotechnol. 2019, 10, 2294–2303, doi:10.3762/bjnano.10.221

• rotates in the XY-plane of the Cartesian coordinates, so that Neglecting weak magnetic damping and a small moment of inertia of a magnetic nanoparticle, the magneto-dynamic equations of motion of the unit vectors and in a viscous fluid have the form [25] where G = K/3η, η is the liquid viscosity, K is

• density ρ = 5 g/cm3, and the viscosity of the liquid η = 0.01 g/(cm·s). The magnetic damping constant is assumed to be κ = 0.1, the medium temperature is T = 300 K. Figure 4 shows that for a dilute assembly of superparamagnetic nanoparticles in RMFs the SAR value monotonously rises with increasing

Influence of the thickness of an antiferromagnetic IrMn layer on the static and dynamic magnetization of weakly coupled CoFeB/IrMn/CoFeB trilayers

• Deepika Jhajhria,
• Dinesh K. Pandya and
• Sujeet Chaudhary

Beilstein J. Nanotechnol. 2018, 9, 2198–2208, doi:10.3762/bjnano.9.206

• that with the increase in IrMn layer thickness a nearly linear enhancement of the effective magnetic damping constant occurs, which is associated with the simultaneous influence of spin pumping and interlayer exchange coupling effects. An extrinsic contribution to the linewidth originating from the two

• . Keywords: ferromagnetic resonance; interlayer exchange coupling; magnetic damping; magnetic thin films; spin pumping; Introduction Traditionally, antiferromagnets (AF) are known to play only a static role by pinning adjacent ferromagnetic (FM) layers via exchange bias in spin-valve devices [1]. Recently

• displacing the resonance field Hr [26][27][28][29]. Spin transport and relaxation studies in FM/AF/FM trilayers are intriguing due to the presence of two interfaces shared between FM and AF. Also, little is known about how effective magnetic damping evolves when there is a weak interlayer exchange coupling

An adapted Coffey model for studying susceptibility losses in interacting magnetic nanoparticles

• Mihaela Osaci and
• Matteo Cacciola

Beilstein J. Nanotechnol. 2015, 6, 2173–2182, doi:10.3762/bjnano.6.223

• calculation and experimental results [21]. This calculation shows the dependence of the relaxation time on the magnetic damping constant α. For the case of most ferromagnetic and ferrimagnetic nanoparticle systems, the magnetic damping constant α exhibits low values (α << 1) [22]. In this section, we adapt