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

Jerzy Krupka, Adam Pacewicz, Bartlomiej Salski, Paweł Kopyt, Jeremy Bourhill, Maxim Goryachev, Michael Tobar

Research output: Contribution to journalArticle

Abstract

Electrodynamic theory applied to the analysis of TEn0p mode resonances in ferrimagnetic spheres placed either in metallic cavities or in the free space is compared with Walker-Fletcher's theory of so-called magnetostatic modes. The influence of the diameter of the sample, its permittivity and the permittivity of the surrounding media on the resonance frequencies of a few modes is analyzed. It is shown that the dominant resonances are essentially related either to negative values of the diagonal component of the permeability tensor or, for clockwise circularly polarized magnetic fields, to negative effective permeability. The electrodynamic theory is used to determine the saturation magnetization (Ms) from measured TEn01 frequency differences. Measurements on different samples confirmed that Ms can be determined using an electrodynamic approach with uncertainties of the order of 2% regardless of sample sizes or metal enclosures if the anisotropy field is negligible compared to the static internal magnetic bias.

Original languageEnglish
Article number165331
JournalJournal of Magnetism and Magnetic Materials
Volume487
DOIs
Publication statusPublished - 1 Oct 2019

Fingerprint

Magnetostatics
Electrodynamics
magnetostatics
Saturation magnetization
electrodynamics
saturation
magnetization
permeability
Permittivity
permittivity
enclosure
Enclosures
Tensors
Anisotropy
Metals
tensors
Magnetic fields
anisotropy
cavities
magnetic fields

Cite this

@article{312a90409b5b4f5e9d12d948a89ff8a1,
title = "Electrodynamic improvements to the theory of magnetostatic modes in ferrimagnetic spheres and their applications to saturation magnetization measurements",
abstract = "Electrodynamic theory applied to the analysis of TEn0p mode resonances in ferrimagnetic spheres placed either in metallic cavities or in the free space is compared with Walker-Fletcher's theory of so-called magnetostatic modes. The influence of the diameter of the sample, its permittivity and the permittivity of the surrounding media on the resonance frequencies of a few modes is analyzed. It is shown that the dominant resonances are essentially related either to negative values of the diagonal component of the permeability tensor or, for clockwise circularly polarized magnetic fields, to negative effective permeability. The electrodynamic theory is used to determine the saturation magnetization (Ms) from measured TEn01 frequency differences. Measurements on different samples confirmed that Ms can be determined using an electrodynamic approach with uncertainties of the order of 2{\%} regardless of sample sizes or metal enclosures if the anisotropy field is negligible compared to the static internal magnetic bias.",
keywords = "Ferromagnetic resonance, Magnetic plasmon, Magnetostatic modes, Saturation magnetization, YIG sphere",
author = "Jerzy Krupka and Adam Pacewicz and Bartlomiej Salski and Paweł Kopyt and Jeremy Bourhill and Maxim Goryachev and Michael Tobar",
year = "2019",
month = "10",
day = "1",
doi = "10.1016/j.jmmm.2019.165331",
language = "English",
volume = "487",
journal = "Journal of Magnetism & Magnetic Materials",
issn = "0304-8853",
publisher = "Elsevier",

}

Electrodynamic improvements to the theory of magnetostatic modes in ferrimagnetic spheres and their applications to saturation magnetization measurements. / Krupka, Jerzy; Pacewicz, Adam; Salski, Bartlomiej; Kopyt, Paweł; Bourhill, Jeremy; Goryachev, Maxim; Tobar, Michael.

In: Journal of Magnetism and Magnetic Materials, Vol. 487, 165331, 01.10.2019.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Electrodynamic improvements to the theory of magnetostatic modes in ferrimagnetic spheres and their applications to saturation magnetization measurements

AU - Krupka, Jerzy

AU - Pacewicz, Adam

AU - Salski, Bartlomiej

AU - Kopyt, Paweł

AU - Bourhill, Jeremy

AU - Goryachev, Maxim

AU - Tobar, Michael

PY - 2019/10/1

Y1 - 2019/10/1

N2 - Electrodynamic theory applied to the analysis of TEn0p mode resonances in ferrimagnetic spheres placed either in metallic cavities or in the free space is compared with Walker-Fletcher's theory of so-called magnetostatic modes. The influence of the diameter of the sample, its permittivity and the permittivity of the surrounding media on the resonance frequencies of a few modes is analyzed. It is shown that the dominant resonances are essentially related either to negative values of the diagonal component of the permeability tensor or, for clockwise circularly polarized magnetic fields, to negative effective permeability. The electrodynamic theory is used to determine the saturation magnetization (Ms) from measured TEn01 frequency differences. Measurements on different samples confirmed that Ms can be determined using an electrodynamic approach with uncertainties of the order of 2% regardless of sample sizes or metal enclosures if the anisotropy field is negligible compared to the static internal magnetic bias.

AB - Electrodynamic theory applied to the analysis of TEn0p mode resonances in ferrimagnetic spheres placed either in metallic cavities or in the free space is compared with Walker-Fletcher's theory of so-called magnetostatic modes. The influence of the diameter of the sample, its permittivity and the permittivity of the surrounding media on the resonance frequencies of a few modes is analyzed. It is shown that the dominant resonances are essentially related either to negative values of the diagonal component of the permeability tensor or, for clockwise circularly polarized magnetic fields, to negative effective permeability. The electrodynamic theory is used to determine the saturation magnetization (Ms) from measured TEn01 frequency differences. Measurements on different samples confirmed that Ms can be determined using an electrodynamic approach with uncertainties of the order of 2% regardless of sample sizes or metal enclosures if the anisotropy field is negligible compared to the static internal magnetic bias.

KW - Ferromagnetic resonance

KW - Magnetic plasmon

KW - Magnetostatic modes

KW - Saturation magnetization

KW - YIG sphere

UR - http://www.scopus.com/inward/record.url?scp=85066437938&partnerID=8YFLogxK

U2 - 10.1016/j.jmmm.2019.165331

DO - 10.1016/j.jmmm.2019.165331

M3 - Article

VL - 487

JO - Journal of Magnetism & Magnetic Materials

JF - Journal of Magnetism & Magnetic Materials

SN - 0304-8853

M1 - 165331

ER -