重金属Pt掺杂Ni₈₀Fe₂₀薄膜体系自旋轨道耦合效应的铁磁共振研究

Ferromagnetic Resonance Studies on Spin-Orbit Coupling Effects in Heavy Metal Pt-Doped Ni₈₀Fe₂₀ Thin Films

摘要: 坡莫合金(Ni₈₀Fe₂₀)具有高磁导率、高饱和磁化强度，低矫顽力等优异的软磁性能，广泛应用于电力电子、精密测量与传感以及自旋电子器件等领域。本文利用磁控溅射技术，制备了Pt掺杂的Pt_x-( Ni₈₀Fe₂₀)_1-x薄膜样品，借助X射线衍射仪、振动样品磁强计(VSM)和铁磁共振仪(FMR)系统研究了Pt掺杂对坡莫合金薄膜样品晶体结构、静态及动态磁学性能的影响规律。研究发现Pt元素掺杂降低了坡莫合金薄膜的饱和磁化强度M_s的同时有效增强了坡莫合金薄膜的垂直磁各向异性场$H_k^{\perp }$ 和Gilbert阻尼α，尤其是α从零掺杂时的0.0079增至13.4%掺杂时的0.015，增幅达83.97%。研究结果表明，Pt元素的引入显著增强了坡莫合金薄膜的自旋轨道耦合效应，有望推动其在磁传感器及自旋电子器件领域的应用。

Abstract: Permalloy (Ni₈₀Fe₂₀) exhibits excellent soft magnetic properties, including high permeability, high saturation magnetization, and low coercivity, making it widely applied in fields such as power electronics, precision measurement and sensing, and spintronic devices. In this work, Pt-doped Pt_x-(Ni₈₀Fe₂₀)_1-x thin films were fabricated using magnetron sputtering technique. The effects of Pt doping concentrations on the crystal structure, static and dynamic magnetic properties of the Permalloy films were systematically investigated using X-ray diffraction (XRD), vibrating sample magnetometry (VSM), and ferromagnetic resonance (FMR) techniques. It was found that the introduction of Pt reduces the saturation magnetization M_s of the Permalloy films while effectively enhancing the perpendicular magnetic anisotropy field $H_k^{\perp }$ and the Gilbert damping constant α. Notably, α increases significantly from 0.0079 in the undoped sample to 0.015 at a doping concentration of 13.4%, corresponding to an increase of 83.97%. The demonstrated results indicate that the incorporation of Pt significantly enhances the spin-orbit coupling effect in Permalloy films, which holds promise for advancing their applications in magnetic sensors and spintronic devices.