Pressure-driven Superconductivity in Transition-metal Pentatelluride HfTe5

TL;DR

This study reports the discovery of pressure-induced superconductivity in HfTe5, a transition-metal pentatelluride, with critical temperature reaching 4.8 K at 20 GPa, revealing new phases and electronic properties under high pressure.

Contribution

It provides the first experimental evidence of superconductivity in HfTe5 under high pressure and details its structural and electronic evolution.

Findings

Superconductivity in HfTe5 appears at around 5 GPa.

Maximum Tc of 4.8 K at 20 GPa.

Superconductivity persists up to 42 GPa.

Abstract

Layered transition-metal tellurides have attracted considerable attention because of their rich physics; for example, tungsten ditelluride WTe2 exhibits extremely large magnetoresistance; the tritelluride ZrTe3 shows a charge density wave transition at low temperature; and the pentatelluride ZrTe5 displays an enigmatic resistivity anomaly and large thermoelectric power. Recently some transition-metal tellurides are predicted to be quantum spin Hall insulators (e.g. ZrTe5 and HfTe5) or Weyl semimetals (e.g. WTe2 and MoTe2) and were subjected to intensive investigations. Here, we report on the discovery of superconductivity in hafnium pentatelluride HfTe5 under high pressure. We observe two structural phase transitions and metallization with superconductivity developing at around 5 GPa. A maximal critical temperature of 4.8 K is attained at a pressure of 20 GPa, and superconductivity persists up to the maximum pressure in our study (42 GPa). Theoretical calculations indicate that the superconductivity develops mainly in the Te atom layers at medium pressure and in the Te atom chains at high pressure.