Ferromagnetic linewidth measurements employing electrodynamic model of the magnetic plasmon resonance. (18th January 2018)

• Record Type: Journal Article
• Authors: Krupka, Jerzy; Aleshkevych, Pavlo; Salski, Bartlomiej; Kopyt, Pawel
• Is Part Of: Measurement science & technology. Volume 29:Number 2(2018:Feb.)
• Publication Date: 2018-01-18
• Subjects: ferromagnetic linewidth -- magnetic plasmon resonance -- magnon-polariton; Physical measurements -- Periodicals; Scientific apparatus and instruments -- Periodicals; Equipment and Supplies -- Periodicals; Science -- instrumentation -- Periodicals; Technology -- instrumentation -- Periodicals; Mesures physiques -- Périodiques; Physical measurements; Scientific apparatus and instruments; Periodicals; 502.87
• DOI: 10.1088/1361-6501/aa990a
• Languages: English
• ISSNs: 0957-0233

Abstract

Abstract: The mode of uniform precession, or Kittel mode, in a magnetized ferromagnetic sphere, has recently been proven to be the magnetic plasmon resonance. In this paper we show how to apply the electrodynamic model of the magnetic plasmon resonance for accurate measurements of the ferromagnetic resonance linewidth Δ H . Two measurement methods are presented. The first one employs Q -factor measurements of the magnetic plasmon resonance coupled to the resonance of an empty metallic cavity. Such coupled modes are known as magnon-polariton modes, i.e. hybridized modes between the collective spin excitation and the cavity excitation. The second one employs direct Q -factor measurements of the magnetic plasmon resonance in a filter setup with two orthogonal semi-loops used for coupling. Q -factor measurements are performed employing a vector network analyser. The methods presented in this paper allow one to extend the measurement range of the ferromagnetic resonance linewidth Δ H well beyond the limits of the commonly used measurement standards in terms of the size of the samples and the lowest measurable linewidths. Samples that can be measured with the newly proposed methods may have larger size as compared to the size of samples that were used in the standard methods restricted by the limits of perturbation theory.