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arXiv · 1804.08786

$\text{Co}_{25}\text{Fe}_{75}$ Thin Films with Ultralow Total Damping

Eric R. J. Edwards·Hans T. Nembach·Justin M. Shaw
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Abstract

We measure the dynamic properties of $\text{Co}_{25}\text{Fe}_{75}$ thin films grown by dc magnetron sputtering. Using ferromagnetic resonance spectroscopy, we demonstrate an ultralow total damping parameter in the out-of-plane configuration of < 0.0013, whereas for the in-plane configuration we find a minimum total damping of < 0.0020. In both cases, we observe low inhomogeneous linewidth broadening in macroscopic films. We observe a minimum full-width half-maximum linewidth of 1 mT at 10 GHz resonance frequency for a 12 nm thick film. We characterize the morphology and structure of these films as a function of seed layer combinations and find large variation of the qualitative behavior of the in-plane linewidth vs. resonance frequency. Finally, we use wavevector-dependent Brillouin light scattering spectroscopy to characterize the spin-wave dispersion at wave vectors up to 23 $μ\text{m}^{-1}$.

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Eric R. J. Edwards, Hans T. Nembach, Justin M. Shaw. 2018-04-24. $\text{Co}_{25}\text{Fe}_{75}$ Thin Films with Ultralow Total Damping. https://doi.org/10.1103/physrevapplied.11.054036

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