Co2FeGe 赫斯勒薄膜中通过缓冲层工程独立调控表面声波与自旋波

中文摘要 AI 辅助

理解和控制磁性薄膜中的声波与自旋波激发对自旋电子学与自旋声学器件的开发至关重要。我们报道了在 MgO(001) 衬底上生长的 Co2FeGe 全赫斯勒薄膜中，利用 Cr 和 W 缓冲层独立调控声学与磁激发的研究。通过布里渊光散射（BLS）光谱与铁磁共振（FMR），我们探测了瑞利和塞扎瓦表面声波（SAW），以及 Damon-Eshbach 和垂直驻留自旋波（PSSW）模式。结果表明，声学色散强烈依赖于缓冲材料：与无缓冲层薄膜相比，W 缓冲层薄膜的瑞利 SAW 频率显著降低 16%，主要源于质量负载与声阻抗变化；缓冲层在大幅改变声学频率的同时，还通过不同物理机制调控动态磁响应，使自旋波群速度提高约 34%。有限元模拟与实验声学数据吻合良好。这些发现证明缓冲层工程是独立调控弹性与磁激发的有效策略，为混合自旋声学技术提供了通用平台。

英文摘要

Understanding and controlling acoustic and spin-wave excitations in magnetic thin films is critical for the development of magnonic and spin-acoustic devices. We report on the use of Cr and W buffer layers to independently modify the acoustic and magnetic excitations in Co2FeGe full-Heusler thin films grown on MgO(001). Using Brillouin light scattering (BLS) spectroscopy and ferromagnetic resonance (FMR), we probed Rayleigh and Sezawa surface acoustic waves (SAWs) alongside Damon-Eshbach and perpendicular standing spin-wave (PSSW) modes. Our results show that acoustic dispersion depends strongly on the buffer material; W-buffered films exhibit a pronounced 16% reduction in Rayleigh SAW frequency compared to buffer-free films, primarily due to mass loading and acoustic impedance shifts. While the buffer layers significantly shift acoustic frequencies, they simultaneously modify the dynamic magnetic response (increasing spin-wave group velocity by ~34%) through different physical mechanisms. Finite-element simulations show excellent agreement with the experimental acoustic data. These findings demonstrate that buffer-layer engineering is an effective strategy for the independent tailoring of elastic and magnetic excitations, providing a versatile platform for hybrid spin-acoustic technologies.

发表机构

• Adam Mickiewicz University（亚当·密茨凯维奇大学）
• Universidade do Porto（波尔图大学）
• Universidad de Zaragoza-CSIC（萨拉戈萨大学-西班牙国家研究委员会）
• NanoBiomedical Centre, Adam Mickiewicz University（纳米生物医学中心，亚当·密茨凯维奇大学）

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