Retention of the high-pressure-induced metastable superconducting phases in Bi*

To investigate the potential industrial application of high pressure superconductivity, the effect of pressure quenching at liquid nitrogen temperature was studied on the non-superconducting single crystal bismuth (Bi) up to 12 GPa, where three superconducting phases are pressure induced. They are the monoclinic phase (Bi-II), tetragonal host-guest phase (Bi-III), and bcc phase (Bi-V), progressively with increase of pressure. Superconducting phases with T_c up to ~ 7 K were retained upon pressure quenching, with Bi-III being the most robust state. The retained superconducting phase stability of Bi-III was tested with thermal cycles. Our results indicate that phase may be related to post-quench residual pressure. The results of pressure quenching experiments demonstrated that metastable phases can be exploited to retain higher T_cs at ambient pressure. Furthermore, this technique also shows potential to quickly map out different metastable phases.