This study demonstrates exceptional magnetic properties associated with magnetic anisotropy in nickel layers approximately 23–28 nm thick, deposited between amorphous silicon layers (a-Si/Ni/a-Si) using triode sputtering. X-ray diffraction (XRD) analyses confirm the presence of the Ni phase in the samples. Furthermore, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) measurements reveal a trilayer structure consisting of nickel and silicon. These techniques also highlight the surface roughness of the nickel layer and detail the characteristics of the Ni/Si interface. Magnetic properties were evaluated using a vibrating sample magnetometer (VSM). The samples were annealed at temperatures up to 190 °C to optimize their magnetic characteristics. After annealing, the samples exhibited a high perpendicular remanence ratio (M_r/M_S ≈ 1), high perpendicular coercivity (H_C = 620 Oe), and a high effective perpendicular magnetic anisotropy energy density (K_eff*t ≈ 1.16 erg/cm²). These properties are particularly interesting because of the substantial thickness of the nickel layer. Achieving nickel films thicker than 15 nm with perpendicular magnetic anisotropy (PMA) has been challenging. The origin of PMA is attributed to magnetoelastic anisotropy and internal strains, which are related to diffusion processes and thermal expansion mismatch between the Ni layer and the Ni/Si and a-Si layers.

中文翻译：

---

沉积在非晶硅层之间的镍膜：退火、Ni/Si 界面和磁性的影响


这项研究表明，使用三极管溅射沉积在非晶硅层 （a-Si/Ni/a-Si） 之间，镍层厚度约为 23-28 nm，镍层的磁各向异性具有优异的磁性。X 射线衍射 （XRD） 分析证实样品中存在 Ni 相。此外，透射电子显微镜 （TEM） 和 X 射线光电子能谱 （XPS） 测量揭示了由镍和硅组成的三层结构。这些技术还突出了镍层的表面粗糙度，并详细说明了 Ni/Si 界面的特性。使用振动样品磁力计 （VSM） 评估磁性能。样品在高达 190 °C 的温度下退火，以优化其磁性。退火后，样品表现出较高的垂直剩磁比 （M_r/M_S ≈ 1）、较高的垂直矫顽力 （H_C = 620 Oe） 和较高的有效垂直磁各向异性能量密度 （K_eff*t ≈ 1.16 erg/cm²）。由于镍层的厚度很大，这些特性特别有趣。使用垂直磁各向异性 （PMA） 实现厚度超过 15 nm 的镍膜一直具有挑战性。PMA 的起源归因于磁弹性各向异性和内部应变，这与 Ni 层与 Ni/Si 和 a-Si 层之间的扩散过程和热膨胀失配有关。