Local structural analysis of In‐doped Bi₂Se₃ topological insulator using X‐ray fluorescence holography

Abstract

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.

Superconductivity in Cu Co-Doped SrxBi2Se3 Single Crystals

“…This intercalating dopant natures of Sr, Cu and Nb impurities in the Bi2Se3 matrix seems to be the key factor for superconductivity. Indeed, many other cationic impurities in Bi2Se3, such as Ag [39] or In [40], readily substitute for bismuth and do not bring superconductivity at ambient pressure.…”

Photosensing and Characterizing of the Pristine and In-, Sn-Doped Bi2Se3 Nanoplatelets Fabricated by Thermal V–S Process

“…The typical structure of Bi 2 Se 3 is layered; each layer comprises five monoatomic planes and is, therefore, a quintuple layer (QL). The QL is denoted as A1-B1-A1'-B1-A1, as shown in Figure 5b [55]. A1 and A1' are the Se atoms; B1 is the Bi atom.…”

Local Structure of the Impurity Site in Nd:LaF3 by X‐Ray Fluorescence Holography

“…Furthermore, the good agreement between experimental data for the Nd and La emitters and the computationally generated model demonstrate that no significant lattice distortions take place around the dopant site. In the light of previous XFH characterizations of the local structure around dopant sites (examples are given in previous studies [ 5–9 ] ), this is a rather unusual situation and may be explained by the stability of the LaF 3 lattice and the same oxidization state of the lanthanides (nominally Nd 3+ and La 3+ ).…”

“…Prominent recent examples where XFH was used to investigate the impurity site are the characterization of lattice distortions around Ga impurity atoms in InSb single crystals, [ 4 ] the determination of the spontaneous formation of suboxidic coordination around Co in ferromagnetic rutile, [ 5 ] the determination of different dopant sites in topological insulators like Mn:Bi 2 Te 3 [ 6 ] and In:Bi 2 Se 3 , [ 7 ] the atomic environment around Ca cations in a doped KTaO 3 wafer, [ 8 ] or studying the effect of heavy element doping of Ta in a Fe 2 VAl Heusler‐type thermoelectric material. [ 9 ] XFH is, however, not limited to impurities, but can also be useful for the investigation of bulk samples, in particular for chalcogenide superconductors [ 10 ] and also in general for determining positional fluctuations of atoms.…”