National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, 305-0044, Japan.
Nanoscale. 2017 Dec 21;10(1):295-301. doi: 10.1039/c7nr07177a.
We realize Mn δ-doping into Si and Si/Ge interfaces using Mn atomic chains on Si(001). Highly sensitive X-ray absorption fine structure techniques reveal that encapsulation at room temperature prevents the formation of silicides/germanides while maintaining one-dimensional anisotropic structures. This is revealed by studying both the incident X-ray polarization dependence and post-annealing effects. Density functional theory calculations suggest that Mn atoms are located at substitutional sites, and show good agreement with experiment. A comprehensive magnetotransport study reveals magnetic ordering within the Mn δ-doped layer, which is observed at around 120 K. We demonstrate that doping methods based on the burial of surface nanostructures allows for the realization of systems for which conventional doping methods fail.
我们使用 Si(001) 上的 Mn 原子链，实现了 Mn δ 在 Si 和 Si/Ge 界面处的掺杂。高灵敏度的 X 射线吸收精细结构技术揭示了室温下的封装可以防止硅化物/锗化物的形成，同时保持一维各向异性结构。这一点通过研究入射 X 射线偏振依赖性和退火后效应得到了证实。密度泛函理论计算表明，Mn 原子位于替位位置，与实验结果吻合较好。全面的磁输运研究揭示了 Mn δ 掺杂层中的磁有序，该磁有序在约 120 K 时被观察到。我们证明，基于表面纳米结构掩埋的掺杂方法可以实现传统掺杂方法无法实现的体系。
