Superconductivity in compressed SnPS3

TL;DR

This study demonstrates that the insulator SnPS3 becomes superconducting under high pressure, expanding the known family of MPX3 superconductors and opening new avenues for exploring emergent electronic phenomena.

Contribution

It provides the first evidence of superconductivity in the trisulfide compound SnPS3 under high pressure, broadening the MPX3 family of superconductors.

Findings

Superconductivity in SnPS3 observed above 31.7 GPa with Tc ~2.2-2.8 K

SnPS3 undergoes an insulator-metal transition near 31.7 GPa

Pressure induces multiple electronic and structural transitions in SnPS3

Abstract

Metal phosphorous trichalcogenides, MPX3, is a group of van der Waals materials with rich electronic properties and even exotic magnetic behavior. These properties can be well manipulated by pressure/strain via effective control of interlayer interaction, lattice parameters and crystal structure. Superconducting transition has been observed in compressed FePSe3. However, it is the only one superconductor reported in the large MPX3 family. Is it possible to achieve superconducting transition in other MPX3 compounds, especially in a trisulfide compound? In this work, we tentatively compressed the SnPS3 (an insulator with large band gap at ambient condition) up to 48.9 GPa, and managed to achieve the superconducting transition above 31.7 GPa with Tc ranging from ~2.2 K to ~2.8 K. The upper critical field is estimated to be ~3.03 T at 40.5 GPa. Optical absorption measurements together with Raman spectroscopy show a series of transitions under pressure, which is well consistent with the electric transport results. This work provides direct experimental evidence that SnPS3 undergoes an insulator-metal transition near 31.7 GPa. More importantly, it demonstrates that superconductivity can exist in MPS3 compounds, which not only further enriches the electronic properties of this kind of material but also paves a new avenue to explore the abundant emergence phenomena in the whole MPX3 family, and it also benefits the study of superconductor mechanism.