A series of Co₂FeSi (CFS) films sandwiched by MgO and Pt layers are sputtered. For the as-deposited films, the magnetic easy axis lies in the sample plane. After annealing, perpendicular magnetic anisotropy (PMA) is shown to build in the stacks with CFS thickness ranged from 2.5 to 3.8 nm and is determined to be the order of 10⁵–10⁶ erg/cm³ in magnitude. The largest saturation magnetization of 1009 ± 41 emu/cm³, close to the bulk value of CFS, is obtained in the annealed stacks. The thickness of a magnetic dead layer is shown to monotonically increase with annealing temperature. This can be ascribed to the progress of the oxidation from the CFS/MgO interface with annealing temperature. No PMA is observed without Pt buffer or MgO top layers. The positive contributions to the PMA made by the Pt/CFS and CFS/MgO interfaces are experimentally verified. The strong PMA is shown to be maintained in the stacks with 4 nm Pt buffer and 0.5 nm MgO layers after high-temperature annealing. Our results provide some useful information on the design for the next generation of CFS-based spintronic devices.

一系列被 MgO 和 Pt 层夹在中间的 Co ₂ FeSi (CFS) 薄膜被溅射。对于沉积的薄膜，易磁轴位于样品平面。退火后，垂直磁各向异性 (PMA) 显示出在 CFS 厚度范围为 2.5 至 3.8 nm 的堆叠中建立，并被确定为数量级为 10 ⁵ –10 ⁶ erg/cm ³。最大饱和磁化强度1009±41emu/cm ³，接近 CFS 的体积值，是在退火堆栈中获得的。磁性死层的厚度显示为随退火温度单调增加。这可以归因于随着退火温度从 CFS/MgO 界面氧化的进展。如果没有 Pt 缓冲液或 MgO 顶层，则没有观察到 PMA。实验验证了 Pt/CFS 和 CFS/MgO 界面对 PMA 的积极贡献。高温退火后，强 PMA 保持在具有 4 nm Pt 缓冲层和 0.5 nm MgO 层的堆叠中。我们的结果为下一代基于 CFS 的自旋电子器件的设计提供了一些有用的信息。