Structure Re-determination and Superconductivity Observation of Bulk 1T MoS2

TL;DR

This study successfully synthesized pure bulk 1T MoS2 crystals, precisely determined their crystal structure, and observed for the first time superconductivity at 4 K in this phase.

Contribution

The paper provides the first experimental demonstration of superconductivity in pure 1T MoS2 and clarifies its crystal structure through single-crystal X-ray diffraction.

Findings

Determined the crystal structure of 1T MoS2 as space group P-3m1.

Observed superconductivity at Tc = 4 K in pure 1T MoS2.

Synthesized high-quality single crystals of 1T MoS2.

Abstract

2H MoS2 has been intensively studied because of layer-dependent electronic structures and novel physical properties. Though the metastable 1T MoS2 with the [MoS6] octahedron was observed from the microscopic area, the true crystal structure of 1T phase has not been determined strictly. Moreover, the true physical properties have not been demonstrated from experiments due to the challenge for the preparation of pure 1T MoS2 crystals. Here, we successfully synthesized the 1T MoS2 single crystals and re-determined the crystal structure of 1T MoS2 from single-crystal X-ray diffraction. 1T MoS2 crystalizes in space group P-3m1 with a cell of a = b = 3.190(3) {\AA} and c = 5.945(6) {\AA}. The individual MoS2 layer consists of MoS6 octahedron sharing edge with each other. More surprisingly, the bulk 1T MoS2 crystals undergo a superconducting transition of Tc = 4 K, which is the first observation of superconductivity in pure 1T MoS2 phase.