Synthesis of Superconducting InxSn1−xTe (0.04 &lt; x &lt; 0.1) Large Single Crystal by Liquid Transport Method

Peng Zhu,Yongkai Li,Xiao Lin,Xin Zhang,Zhiwei Wang,Xiaohui Yang,Ying Yang,Xiang Li,Fan Yang

doi:10.3390/cryst11050474

Synthesis of Superconducting InxSn1−xTe (0.04 < x < 0.1) Large Single Crystal by Liquid Transport Method

Peng Zhu, Yongkai Li + Show 7 more

Open Access

https://doi.org/10.3390/cryst11050474

Copy DOI

Abstract

In this work, a new crystal growth technique called the liquid transport method was introduced to synthesize single crystals of a topological superconductor candidate, InxSn1−xTe (IST). Crystals with the size of several millimeters were successfully synthesized, and were characterized by X-ray diffraction, scanning electron microscopy with energy-dispersive spectroscopy as well as electronic transport measurements. Lattice parameters decreased monotonously with the increase of indium content while hole density varied in reverse. Superconductivity with the critical temperature (Tc) around 1.6 K were observed, and the hole densities were estimated to be in the order of 1020 cm−3. The upper critical fields (Bc2) were estimated to be 0.68 T and 0.71 T for In0.04Sn0.96Te and In0.06Sn0.94Te, respectively. The results indicated that the quality of our crystals is comparable to that grown by the chemical vapor transport method, but with a relatively larger size. Our work provides a new method to grow large single crystals of IST and could help to solve the remaining open questions in a system that needs large crystals, such as a superconducting pairing mechanism, unconventional superconductivity, and so on.

Highlights

Topological insulators (TIs) and topological crystalline insulators (TCIs) have been attracting great attention because of their novel gapless surface states which are protected by time-reversal symmetry and crystalline mirror symmetry [1,2,3,4,5], respectively
The doped Ax Bi2 Se3 are not suitable for developing devices because the superconductivity in these topological superconductor (TSC) candidates are very fragile against air exposure, mechanical force, and heating
The above starting materials were sealed in a quartz tube (Jinghui, Lianyungang, Jiangsu, China), respectively, with hydrogen of 0.8 atm, and they were annealed at a temperature 50 K lower than their melting point for 10 h

Summary

Introduction

Topological insulators (TIs) and topological crystalline insulators (TCIs) have been attracting great attention because of their novel gapless surface states which are protected by time-reversal symmetry and crystalline mirror symmetry [1,2,3,4,5], respectively These gapless surface states originate from a non-zero topological invariant of the bulk energy bands, and have great potential applications in spintronics, dissipationless transport, photoelectric detection, and so on. It is clear that the polycrystalline sample shows more disorder than the single crystal and impurity favors higher indium doping samples. IST is topological or not, large single crystals with lower indium doping are desirable. We expect the IST single crystals grown by this method could help remaining open questions in this system to be answered

Experimental Methods

Results and Discussion

1.57 K and of