Ferromagnetic resonance study of sputtered Co|Ni multilayers

J. M L Beaujour, W. Chen, K. Krycka, C. C. Kao, J. Z. Sun, A. D. Kent

    Research output: Contribution to journalArticle

    Abstract

    We report on room temperature ferromagnetic resonance (FMR) studies of [ t Co|2t Ni] ∈×∈N sputtered films, where 0.1 ≤ t ≤ 0.6 nm. Two series of films were investigated: films with the same number of Co|Ni bilayer repeats (N = 12), and samples in which the overall magnetic layer thickness is kept constant at 3.6 nm (N = 1.2/t). The FMR measurements were conducted with a high frequency broadband coplanar waveguide up to 50 GHz using a flip-chip method. The resonance field and the full width at half maximum were measured as a function of frequency for the field in-plane and field normal to the plane, and as a function of angle to the plane for several frequencies. For both sets of films, we find evidence for the presence of first and second order anisotropy constants, K 1 and K 2. The anisotropy constants are strongly dependent on the thickness t, and to a lesser extent on the total thickness of the magnetic multilayer. The Landé g-factor increases with decreasing t and is practically independent of the multilayer thickness. The magnetic damping parameter α, estimated from the linear dependence of the linewidth ΔH, on frequency, in the field in-plane geometry, increases with decreasing t. This behaviour is attributed to an enhancement of spin-orbit interactions with decreasing Co layer thickness and in thinner films, to a spin-pumping contribution to the damping.

    Original languageEnglish (US)
    Pages (from-to)475-483
    Number of pages9
    JournalEuropean Physical Journal B
    Volume59
    Issue number4
    DOIs
    StatePublished - Oct 2007

    Fingerprint

    Ferromagnetic resonance
    ferromagnetic resonance
    Multilayers
    Anisotropy
    Damping
    Magnetic multilayers
    magnetic damping
    Coplanar waveguides
    Full width at half maximum
    anisotropy
    Linewidth
    Orbits
    spin-orbit interactions
    pumping
    Thin films
    damping
    chips
    Geometry
    broadband
    waveguides

    ASJC Scopus subject areas

    • Condensed Matter Physics
    • Electronic, Optical and Magnetic Materials

    Cite this

    Beaujour, J. M. L., Chen, W., Krycka, K., Kao, C. C., Sun, J. Z., & Kent, A. D. (2007). Ferromagnetic resonance study of sputtered Co|Ni multilayers. European Physical Journal B, 59(4), 475-483. https://doi.org/10.1140/epjb/e2007-00071-1

    Ferromagnetic resonance study of sputtered Co|Ni multilayers. / Beaujour, J. M L; Chen, W.; Krycka, K.; Kao, C. C.; Sun, J. Z.; Kent, A. D.

    In: European Physical Journal B, Vol. 59, No. 4, 10.2007, p. 475-483.

    Research output: Contribution to journalArticle

    Beaujour, JML, Chen, W, Krycka, K, Kao, CC, Sun, JZ & Kent, AD 2007, 'Ferromagnetic resonance study of sputtered Co|Ni multilayers', European Physical Journal B, vol. 59, no. 4, pp. 475-483. https://doi.org/10.1140/epjb/e2007-00071-1
    Beaujour, J. M L ; Chen, W. ; Krycka, K. ; Kao, C. C. ; Sun, J. Z. ; Kent, A. D. / Ferromagnetic resonance study of sputtered Co|Ni multilayers. In: European Physical Journal B. 2007 ; Vol. 59, No. 4. pp. 475-483.
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