Impurity position and lattice distortion in a Mn-doped Bi2Te3 topological insulator investigated by x-ray fluorescence holography and x-ray absorption fine structure
Impurity position and lattice distortion in a Mn-doped Bi2Te3 topological insulator investigated by x-ray fluorescence holography and x-ray absorption fine structure
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X射线荧光全息术和X射线吸收精细结构研究Mn掺杂Bi2Te3拓扑绝缘体中的杂质位置和晶格畸变
DOI：
10.1103/physrevb.96.214207
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发表时间：
2017
影响因子：
3.7
通讯作者：
and M. Sasaki
中科院分区：
文献类型：
--
作者：
S. Hosokawa;J. R. Stellhorn;T. Matsushita;N. Happo;K. Kimura;K. Hayashi;Y. Ebisu;T. Ozaki;H. Ikemoto;H. Setoyama;T. Okajima;Y. Yoda;H. Ishii;Y.-F. Liao;M. Kitaura;and M. Sasaki
在100和300 K的温度下，对单晶进行了mnx荧光全息（XFH）测量，以寻找该功能晶体中Mn原子的杂质位点。利用正则化线性回归重建三维原子图像。在30-300 K下进行了x射线吸收精细结构（XAFS）实验，以获得更多的结构信息。从这些数据中获得了局部结构信息，如Mn杂质位的位置、Mn- te原子间距离、晶格畸变以及杂质Mn原子周围的位置波动。可能存在的Mn杂质位点有两个，即具有八面体对称的层间位点和层表面Te的取代位点。在取代位杂质Mn原子的位置波动中可以看到明显的温度依赖性。这些杂质位点的发现不能很容易地通过衍射或XAFS实验以通常的方式获得，而只能使用XFH和XAFS测量的组合。
Mnx-ray fluorescence holography (XFH) measurements were performed on a single crystal of atopological insulator at 100 and 300 K to search for the impurity sites of the Mn atoms in this functional crystal. The three-dimensional atomic images were reconstructed using an-regularized linear regression. X-ray absorption fine-structure (XAFS) experiments were also carried out at 30–300 K to obtain additional structural information. The local structural information was obtained from these data, such as the positions of the Mn impurity sites, the Mn-Te interatomic distances, the lattice distortions, and the positional fluctuations around the impurity Mn atoms. The possible Mn impurity sites are twofold, i.e., an interlayer site with an octahedral symmetry and a substitutional site of Te on the layer surface. A distinct temperature dependence is seen in the positional fluctuations of the impurity Mn atoms in the substitutional site. These findings for the impurity sites cannot be easily obtained by diffraction or XAFS experiment in the usual way, but only using a combination of the XFH and XAFS measurements.