Electrodynamic improvements to the theory of magnetostatic modes in ferrimagnetic spheres and their applications to saturation magnetization measurements

Křupka, J.; Pacewicz, Adam; Salski, Bartłomiej; Kopyt, P.; Bourhill, Jeremy; Goryachev, Maxim; Tobar, Michael E.

doi:10.1016/j.jmmm.2019.165331

Cited by 15 publications

(11 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 6a shows measurement results of the transmission spectrum of a monocrystalline YIG sphere (M S = 140 kA/m, d = 0.5 mm, ε r = 16) under a static externally applied magnetic field bias (H ext ≈ 217 kA/m). Details of the experimental setup have been presented in an earlier paper [23]. It is seen that highest peaks on the transmission spectrum correspond to the first three plasmon modes.…”

Section: Experiments and Remarks On Q-factor Computationsmentioning

confidence: 99%

See 1 more Smart Citation

Mode spectra of magnetic and dielectric plasmon spheres obtained from Mie scattering and free oscillation theories

et al. 2021

Self Cite

View full text Add to dashboard Cite

This paper presents Mie scattering theory as compared to rigorous electromagnetic theory of free oscillations in magnetic and electric plasmon spheres. It is shown that the maxima of Mie scattering and absorption spectra well correspond to resonance frequencies of plasmon modes occurring in dielectric and magnetic spheres, similarly as it takes place for ordinary dielectric resonator modes. Mie theory is well applicable to determine resonance frequencies and scattering parameters of spherical plasmons. However, this theory cannot be applied to determine intrinsic properties of modes induced in the object by the incident plane wave, like quality factors. On the contrary, rigorous electromagnetic theory of free oscillations allows one to determine the complex resonance frequency of each mode that can occur in a given object, and the corresponding quality factor accounting for various kind of losses, including medium and radiation losses. The advantage of the free oscillations theory, as shown in this paper, is in the determination of the quality factors of modes occurring in magnetic plasmon spheres made of a strongly dispersive magnetic medium. Graphical Abstract

show abstract

Section: Experiments and Remarks On Q-factor Computationsmentioning

confidence: 99%

“…It is seen that highest peaks on the transmission spectrum correspond to the first three plasmon modes. From the measured resonance frequencies corresponding to these peaks, the saturation magnetization of the sample has been determined with a high precision [23].…”

Section: Experiments and Remarks On Q-factor Computationsmentioning

confidence: 99%

Mode spectra of magnetic and dielectric plasmon spheres obtained from Mie scattering and free oscillation theories

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…Some of these modes can also be analyzed using the magnetodynamic TDE. Details can be found in [25].…”

Section: Determination Of Magnetic Parametersmentioning

confidence: 99%

“…where H a is the effective anisotropy field, dependent on the orientation of the bias field with respect to the anisotropy axes, d is the sample diameter, r its dielectric constant, and c 0 the speed of an EM wave in vacuum. One should keep in mind that using (10) one cannot analyze the influence of adjacent conductors or dielectrics, however these factors can be considered via a magnetodynamic transcendental equation (TDE) [10], [25] formulated for the shielded isotropic sphere.…”

mentioning

confidence: 99%

Electromagnetic Characterization of Shielded Spherical Gyromagnetic Resonators

Pacewicz

Salski

Křupka

et al. 2022

IEEE Trans. Microwave Theory Techn.

Self Cite

View full text Add to dashboard Cite

The electromagnetic (EM) properties of shielded gyromagnetic spheres are characterized with the aid of an electrodynamic model formulated for the transverse electric (TE) modes of an isotropic sphere, in a similar way as dielectric resonators are commonly analyzed. Broadband characteristics of geometric and energy filling factors are presented. A new measure of the magnetic loss tangent is introduced which is positive despite the intrinsic permeability of the gyromagnetic medium being negative, where existing definitions yield a nonphysical negative value. The sample size dependence of those quantities is also assessed. The conclusions from the analysis are applied to investigate and de-embed ferromagnetic linewidth errors which can occur in broadband measurements of magnetic garnet spheres. Magnetic anisotropy fields and the gyromagnetic g-factor are also estimated from the measurement data. Experiments were performed in a two-port subwavelength cavity, covering a frequency range of up to 28 GHz. Additionally, twoport rectangular resonant cavity linewidth measurements at a few modes have been conducted. Good agreement between the two methods is found if the systematic error is accounted for.

show abstract

“…More involved constitutive relations appear in two main scenarios: (i) anisotropic media, where electric permittivity and magnetic permeability become tensors (cf. uniaxial and biaxial crystals [3][4][5][6][7], Weyl semimetals [8,9], and magnetized materials [10,11]); (ii) novel effects in matter described by extended constitutive relations that introduce additional electric and magnetic responses, encoded as linear functions of the type D = D(E, B) and H = H(E, B), in general. This happens, for instance, in bi-isotropic media [12][13][14][15], chiral materials [16], topolog-ical insulators [17][18][19][20][21][22], relativistic electron gases [23], axion electrodynamics [24][25][26], and Lorentz-violating electrodynamics [27,28], as well.…”

Section: Introductionmentioning

confidence: 99%

Effects of CPT-odd terms of dimensions three and five on electromagnetic propagation in continuous matter

Silva,

Lisboa-Santos,

Ferreira

et al. 2021

Preprint

View full text Add to dashboard Cite

In this work we study how CPT -odd Maxwell-Carroll-Field-Jackiw (MCFJ) electrodynamics as well as a dimension-5 extension of it affect the optical activity of continuous media. The starting point is dimension-3 MCFJ electrodynamics in matter whose modified Maxwell equations, permittivity tensor, and dispersion relations are recapitulated. Corresponding refractive indices are achieved in terms of the frequency and the vector-valued background field. For a purely timelike background, the refractive indices are real. Their associated propagation modes are circularly polarized and exhibit birefringence. For a purely spacelike background, one refractive index is always real and the other can be complex. The circularly polarized propagating modes may exhibit birefringence and dichroism (associated with absorption). Subsequently, we examine a dimension-five MCFJ-type electrodynamics, previously scrutinized in the literature, in a continuous medium. Following the same procedure, we find the refractive indices from a sixth-order dispersion equation. For a purely timelike background, three distinct refractive indices are obtained, one of them being real and two being complex. They are associated with two circularly polarized propagating modes that exhibit birefringence or dichroism, depending on the frequency range. Scenarios of propagation and absorption analogous to those found in dispersive dielectrics are also observed for spacelike background configurations. We conclude by comparing the dimension-three and five results and by emphasizing the richer phenomenology of the propagating modes in the higher-derivative model. Our results are applicable in the realm of Weyl semimetals.

show abstract

Electrodynamic improvements to the theory of magnetostatic modes in ferrimagnetic spheres and their applications to saturation magnetization measurements

Cited by 15 publications

References 21 publications

Mode spectra of magnetic and dielectric plasmon spheres obtained from Mie scattering and free oscillation theories

Mode spectra of magnetic and dielectric plasmon spheres obtained from Mie scattering and free oscillation theories

Electromagnetic Characterization of Shielded Spherical Gyromagnetic Resonators

Effects of CPT-odd terms of dimensions three and five on electromagnetic propagation in continuous matter

Contact Info

Product

Resources

About