Electrodynamic improvements to the theory of magnetostatic modes in ferrimagnetic spheres and their applications to saturation magnetization measurements
Jerzy Krupka , Adam Pacewicz , Bartłomiej Wacław Salski , Paweł Kopyt , J. Bourhill , Maxim Goryachev , Michael E. Tobar
AbstractElectrodynamic 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 TEno1 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.
|Journal series||Journal of Magnetism and Magnetic Materials, ISSN 0304-8853, e-ISSN 1873-4766|
|No||1 October 2019|
|Publication size in sheets||0.5|
|License||Journal (articles only); author's original; ; before publication|
|Score||= 100.0, 22-06-2020, ArticleFromJournal|
|Publication indicators||= 2; = 1; = 2.0; : 2018 = 1.239; : 2018 = 2.683 (2) - 2018=2.597 (5)|
|Citation count*||2 (2020-08-14)|
* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.