Pressure-induced anomalous enhancement in superconducting critical temperature of transition-metal chalcogenide Ta$_2$PdS$_6$ and Ta$_2$PdSe$_6$

Ryo Matsumoto; Akitoshi Nakano; Takafumi D Yamamoto; Kensei Terashima; Kazuki Yamane; Masahiro Ohkuma; Ichiro Terasaki; Yoshihiko Takano

paper

Pressure-induced anomalous enhancement in superconducting critical temperature of transition-metal chalcogenide Ta $_{2}$ PdS $_{6}$ and Ta $_{2}$ PdSe $_{6}$

arXiv:2411.01149

Abstract

The emergence of a second dome in the superconducting phase through pressure-driven manipulation of crystal structures in materials has attracted considerable attention. Transition metal chalcogenides (TMCs) represent a highly promising platform, as the second dome has been observed in several binary compounds. Recently, ternary TMCs such as Ta $_{2}$ PdS $_{6}$ and Ta $_{2}$ PdSe $_{6}$ have exhibited pressure-induced superconducting domes. In this study, we perform electrical transport measurements of Ta $_{2}$ PdS $_{6}$ and Ta $_{2}$ PdSe $_{6}$ under extremely high pressures exceeding 100 GPa, namely uninvestigated regions in previous reports, to reveal the emergence of the second dome. The superconducting critical temperatures (T $_{c}$ ) in both Ta $_{2}$ PdS $_{6}$ and Ta $_{2}$ PdSe $_{6}$ initially decrease with increasing pressure. Subsequently, the Tcs tend to enhance drastically above 100 GPa. Notably, the maximum T $_{c}$ in Ta $_{2}$ PdS $_{6}$ is 11.2 K at 130.0 GPa, which is a relatively high record among the TMCs. The emergence of the second dome in Ta $_{2}$ PdS $_{6}$ and Ta $_{2}$ PdSe $_{6}$ opens further motivation for the investigation under extreme conditions beyond the first dome to find hidden ordered phases.

Pressure-induced anomalous enhancement in superconducting critical temperature of transition-metal chalcogenide Ta2​PdS6​ and Ta2​PdSe6​

Abstract

Pressure-induced anomalous enhancement in superconducting critical temperature of transition-metal chalcogenide Ta $_{2}$ PdS $_{6}$ and Ta $_{2}$ PdSe $_{6}$