Magnon dispersion in the spintronic alloys Co50Fe50 and Co20Fe60B20

Co50Fe50 (CF) and Co20Fe60B20 (CFB) have generated a lot of interest in the spintronics/magnonics/spin caloritronics community due to their hard magnetic nature, low magnon linewidth and ease of thin film fabrication. We have studied the spin Seebeck effect (SSE) in Si/CF/Pt and Si/CFB/Pt thin films and have obtained large thermomagnetic responses showing promise for energy harvesting applications. Since the SSE is governed by magnon propagation, it is important to study low and high energy magnon modes for determining SSE efficiency. We have measured the low energy magnon modes in these films using ferromagnetic resonance and have obtained low magnon damping. We now aim to study the high energy magnon propagation in CF and CFB powders using inelastic neutron scattering on the MAPS instrument to form a complete picture of the SSE in these materials and aid in technological applications.

Co₅₀Fe₅₀（CF）与Co₂₀Fe₆₀B₂₀（CFB）因具备硬磁特性、低磁子线宽且易于制备薄膜，在自旋电子学（spintronics）/磁子学（magnonics）/自旋热电子学（spin caloritronics）领域受到广泛关注。我们针对Si/CF/Pt与Si/CFB/Pt薄膜中的自旋塞贝克效应（spin Seebeck effect, SSE）开展了研究，观测到显著的热磁响应，展现出在能量收集领域的应用潜力。由于自旋塞贝克效应由磁子传播主导，研究低能与高能磁子模式对解析自旋塞贝克效应的效率至关重要。我们已通过铁磁共振（ferromagnetic resonance）表征了此类薄膜中的低能磁子模式，并测得较低的磁子阻尼。本研究后续拟利用MAPS谱仪上的非弹性中子散射技术，对CF与CFB粉末中的高能磁子传播行为展开研究，以完整阐明此类材料中自旋塞贝克效应的物理机制，并为其技术应用提供支撑。