Decompression-Driven Superconductivity Enhancement in In<sub>2</sub> Se<sub>3</sub>.

Ke, Feng; Dong, Haini; Chen, Yabin; Zhang, Jianbo; Liu, Cailong; Zhang, Junkai; Gan, Yuan; Han, Yonghao et al. · Adv Mater · 2017

basic_science · Level V

Where this comes from

Abstract

An unexpected superconductivity enhancement is reported in decompressed In<sub>2</sub> Se<sub>3</sub> . The onset of superconductivity in In<sub>2</sub> Se<sub>3</sub> occurs at 41.3 GPa with a critical temperature (T<sub>c</sub> ) of 3.7 K, peaking at 47.1 GPa. The striking observation shows that this layered chalcogenide remains superconducting in decompression down to 10.7 GPa. More surprisingly, the highest T<sub>c</sub> that occurs at lower decompression pressures is 8.2 K, a twofold increase in the same crystal structure as in compression. It is found that the evolution of T<sub>c</sub> is driven by the pressure-induced R-3m to I-43d structural transition and significant softening of phonons and gentle variation of carrier concentration combined in the pressure quench. The novel decompression-induced superconductivity enhancement implies that it is possible to maintain pressure-induced superconductivity at lower or even ambient pressures with better superconducting performance.