There is a growing interest in mixing spintronics and superconductivity to develop original energy-efficient nonvolatile memory and logic devices. Research works conducted so far have mostly focused on superconductor with critical temperature Tc lower than 10 K. Here, we report on the growth and characterization of MgB2/Ni80Fe20 and MgB2/Co bilayers, where Tc of the MgB2 layer is of the order of 30 K. Ferromagnetic resonance was undertaken to analyze the spin pumping into MgB2. The larger magnetization at saturation in Co, as compared to Ni80Fe20, induces a smaller spin pumping contribution to the damping when MgB2 is normal. A spin pumping reduction was observed for both bilayers when MgB2 becomes superconductor and is attributed to the opening of the superconducting gap. The present results show that MgB2 thin films could be suitable to implement superconducting spintronic at 30 K, which is not only relevant for future technological development but also relaxes experimental constraints related to low-temperature investigations.

中文翻译：

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MgB2-超导体/铁磁体界面处的自旋注入


人们越来越关注混合自旋电子学和超导性，以开发原创的节能非易失性存储器和逻辑器件。迄今为止进行的研究工作主要集中在临界温度 Tc 低于 10 K 的超导体上。在这里，我们报告了 MgB2/Ni80Fe20 和 MgB2/Co 双层的生长和表征，其中 MgB2 层的 Tc 约为 30 K。进行了铁磁共振以分析自旋泵浦到 MgB2 中。与 Ni80Fe20 相比，Co 饱和时的磁化强度较大，当 MgB2 正常时，对阻尼的自旋泵浦贡献较小。当 MgB2 成为超导体时，观察到两个双层的自旋泵浦减少，这归因于超导间隙的打开。目前的结果表明，MgB2 薄膜可能适合在 30 K 下实现超导自旋电子学，这不仅与未来的技术发展有关，而且放宽了与低温研究相关的实验限制。