Synthesis of superconducting in_x sn_1−x te (0.04 < x < 0.1) large single crystal by liquid transport method

In this work, a new crystal growth technique called the liquid transport method was introduced to synthesize single crystals of a topological superconductor candidate, In_x Sn_1−x Te (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 (T_c ) 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 (B_c2 ) were estimated to be 0.68 T and 0.71 T for In_0.04 Sn_0.96 Te and In_0.06 Sn_0.94 Te, 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.