Ferromagnetic Relaxation. I. Theory of the Relaxation of the Uniform Precession and the Degenerate Spectrum in Insulators at Low Temperatures

Sparks, M.; Loudon, R.; Kittel, C.

doi:10.1103/physrev.122.791

Cited by 250 publications

(134 citation statements)

References 21 publications

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“…This complicates the quantitative comparison of calculated values for the damping to experimental data since there are many extrinsic contributions to the damping that result from sample structure, measurement geometry, and/or sample properties. While some extrinsic contributions to the damping and linewidth were discovered in the 1960s and 1970s, and are well described by theory, e.g., eddy-current damping [13,14], two-magnon scattering [15][16][17], the slow relaxer mechanism [18,19], or radiative damping [20,21], interest in these mechanisms has been re-ignited recently [22,23]. Further contributions, such as spin pumping, both extrinsic [24,25] and intrinsic [24,26], have been discovered more recently and are subject to extensive research [27][28][29][30][31] for spintronics application.…”

Section: Introductionmentioning

confidence: 83%

Magnetic properties in ultrathin 3d transition-metal binary alloys. II. Experimental verification of quantitative theories of damping and spin pumping

et al. 2017

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General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. A systematic experimental study of Gilbert damping is performed via ferromagnetic resonance for the disordered crystalline binary 3d transition-metal alloys Ni-Co, Ni-Fe, and Co-Fe over the full range of alloy compositions. After accounting for inhomogeneous linewidth broadening, the damping shows clear evidence of both interfacial damping enhancement (by spin pumping) and radiative damping. We quantify these two extrinsic contributions and thereby determine the intrinsic damping. The comparison of the intrinsic damping to multiple theoretical calculations yields good qualitative and quantitative agreement in most cases. Furthermore, the values of the damping obtained in this study are in good agreement with a wide range of published experimental and theoretical values. Additionally, we find a compositional dependence of the spin mixing conductance.

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Section: Introductionmentioning

confidence: 83%

Magnetic properties in ultrathin 3d transition-metal binary alloys. II. Experimental verification of quantitative theories of damping and spin pumping

et al. 2017

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“…The spin relaxation processes are classified as two, three, and four magnon processes, as they are represented by the terms in the spin-wave Hamiltonian that are of second, third, and fourth order, respectively, in the spin-wave amplitudes. 47,48 The two-magnon scattering, which is extrinsic, arise from the inhomogeneities in the material, such as crystal imperfections, randomly oriented crystallites, porosity, surface roughness, and impurities. This is the dominant loss mechanism in coarse-grain sintered polycrystalline ferrites with a small porosity and low Table 7).…”

Section: Equation 103mentioning

confidence: 99%

Microwave ferrites, part 1: fundamental properties

Özgür

Alivov

Morkoç̌

2009

J Mater Sci: Mater Electron

317

110

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Ferrimagnets having low RF loss are used in passive microwave components such as isolators, circulators, phase shifters, and miniature antennas operating in a wide range of frequencies (1-100 GHz) and as magnetic recording media owing to their novel physical properties. Frequency tuning of these components has so far been obtained by external magnetic fields provided by a permanent magnet or by passing current through coils. However, for high frequency operation the permanent part of magnetic bias should be as high as possible, which requires large permanent magnets resulting in relatively large size and high cost microwave passive components. A promising approach to circumvent this problem is to use hexaferrites, such as BaFe 12 O 19 and SrFe 12 O 19 , which have high effective internal magnetic anisotropy that also contributes to the permanent bias.Such a self-biased material remains magnetized even after removing the external applied magnetic field, and thus, may not even require an external permanent i

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“…Although the speci c equation is not shown here, the term f(cos4ϕ M ) results in fourfold symmetry. In these lms, ΔH represents the superposition of several different line broadening mechanisms, and therefore the contributions from ϕ H -independent broadening due to magnetic inhomogeneity (ΔH 0 ), Gilbert damping (ΔH Gilbert ), distribution of anisotropy (ΔH ΔϕH ) and two-magnon scattering (ΔH 2mag ) 16) were considered in this model, as follows…”

Section: Resultsmentioning

confidence: 99%

Anisotropic FMR Linewidths in Epitaxially Grown Si-Doped <i>A</i>2-Fe Thin Films

2016

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A series of 40 nm-thick Fe 100−x Si x (x = 0, 6 or 10 at%) single-crystal lms with an A2 phase were fabricated on MgO(001) substrates. Variations in the ferromagnetic resonant eld (H r ) and linewidth (ΔH) values with changes in the azimuthal angle (ϕ H ) were subsequently evaluated, using an electron cyclotron resonant system with X-band (9.86 GHz) microwaves at room temperature. The H r values exhibited fourfold symmetric behavior while varying the ϕ H . In addition, the ΔH values demonstrated symmetric behavior, with intense peaks in the vicinity of the magnetization hard-axis, and so the ΔH variation was reduced with increasing Si content. An analysis of the data was performed, employing the magnetization coherent rotation model. It was determined that the appearance of strong peaks can be attributed to differences between ϕ H and the magnetization angle (ϕ M ), based on the term [cos. This is believed to result from the insuf cient H r strength obtained during measurements with X-band microwaves relative to the anisotropy elds of the lms.

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Ferromagnetic Relaxation. I. Theory of the Relaxation of the Uniform Precession and the Degenerate Spectrum in Insulators at Low Temperatures

Cited by 250 publications

References 21 publications

Magnetic properties in ultrathin 3d transition-metal binary alloys. II. Experimental verification of quantitative theories of damping and spin pumping

Magnetic properties in ultrathin 3d transition-metal binary alloys. II. Experimental verification of quantitative theories of damping and spin pumping

Microwave ferrites, part 1: fundamental properties

Anisotropic FMR Linewidths in Epitaxially Grown Si-Doped <i>A</i>2-Fe Thin Films

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