Local structural analysis of In-doped Bi2Se3 topological insulator using X-ray fluorescence holography
Local structural analysis of In-doped Bi2Se3 topological insulator using X-ray fluorescence holography
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DOI：
10.1002/sia.6544
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发表时间：
2019-01-01
影响因子：
1.7
通讯作者：
Tajiri, Hiroo
中科院分区：
文献类型：
--
作者：
Kimura, Koji;Hayashi, Koichi;Tajiri, Hiroo
我们对 In 掺杂 Bi2Se3 拓扑绝缘体进行了 X 射线荧光全息测量，并获得了 In 附近的面内原子图像。我们发现第一近邻（NN）位置的原子图像非常弱，而第二和第三近邻（NN）位置的原子图像相对较强。基于In是Bi原子序数的一半这一事实，我们将这一特征的起源归因于In原子在Bi平面上的聚集。我们计算了原子图像的强度，并证实In簇的形成导致第一个NN原子图像强度下降了30%。然而，幅度的减小不足以解释实验结果，这表明了另一个贡献，例如晶格畸变。在模拟的基础上讨论了晶格畸变对原子图像强度的影响，包括In原子的位置涨落。
We performed X-ray fluorescence holography measurements on an In-doped Bi2Se3 topological insulator and obtained an in-plane atomic image in the vicinity of In. We found that atomic images at the positions of the first nearest neighbors (NNs) are very weak whereas those at the positions of the second and the third NNs are relatively strong. On the basis of the fact that In is half of the atomic number of Bi, we attributed the origin of this feature to the clustering of the In atoms in the Bi plane. We calculated the intensity of the atomic images and confirmed that the formation of In cluster results in a decrease by 30% in the first NN atomic image intensity. However, the decrease in the magnitude is not enough to explain the experimental results, suggesting another contribution such as the lattice distortions. The effect of the lattice distortion on the atomic image intensity is discussed on the basis of the simulation including the positional fluctuation of In atoms.