Reversible pressure-induced phase change in eutectic GeSb

In phase-change materials (PCM), typically Ge-Te-Sb based glassy semiconductors, a reversible transformation between a highly resistive (amorphous) and a highly conductive (crystalline) phase is accomplished by Joule heating that melt-quenches PCM into the amorphous state, and thermally anneals it back to the crystalline state. Here we report a room-temperature pressure driven \emph{reversible} phase change in a binary eutectic GeSb system. From structural and Raman spectroscopy studies, we demonstrate abrupt hysteretic amorphous-to-crystalline and intra- crystalline transitions under a compressive load---unique to the Te-free system---that access with pressure the two extreme GeSb states previously obtained by thermal programming. Using \emph {ab-initio} molecular dynamics simulations we show that the reverse process occurs under a tensile load. The role of the Peierls gap and Anderson localization in the pressure induced phase change accompanying a metal-insulator transition will be discussed.