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arXiv · 1808.08466

Twisted magnetization states and inhomogeneous resonance modes in a Fe/Gd ferrimagnetic multilayer

A. B. Drovosekov·A. O. Savitsky·D. I. Kholin·N. M. Kreines·V. V. Proglyado·M. V. Ryabukhina·E. A. Kravtsov·V. V. Ustinov
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Abstract

Static and dynamic magnetic properties of a ferrimagnetic [Fe(35A)/Gd(50A)]x12 superlattice were investigated in a wide 4-300 K temperature range using magneto-optical Kerr effect (MOKE) and ferromagnetic resonance (FMR) techniques. The multilayer structure was sputtered on a transparent glass substrate which made it possible to perform MOKE measurements on both Fe and Gd terminated sides of the superlattice. These experiments allowed us to detect a transition between field-aligned and canted magnetic states on both sides of the film and to distinguish between the bulk and surface twisted phases of the superlattice. As a result, the experimental H-T magnetic phase diagram of the system was obtained. FMR studies at frequencies 7-36 GHz demonstrated a complex evolution of absorption spectra as temperature decreased from room down to 4 K. Two spectral branches were detected in the sample. Theoretical simulations show that the observed spectral branches correspond to different types of inhomogeneous resonance modes in the multilayer with non-uniform magnetization precession inside Gd layers.

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A. B. Drovosekov, A. O. Savitsky, D. I. Kholin, N. M. Kreines, V. V. Proglyado, M. V. Ryabukhina, E. A. Kravtsov, V. V. Ustinov. 2018-08-25. Twisted magnetization states and inhomogeneous resonance modes in a Fe/Gd ferrimagnetic multilayer. https://doi.org/10.1016/j.jmmm.2018.12.022

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