Superconductivity in GeSb2Te4 at elevated pressure

  Bar Hen [1]  ,  Eran Greenberg [1]  ,  Samar Layek [1]  ,  Irina Pozin [2]  ,  Roee Friedman [3]  ,  Victor Shelukhin [1]  ,  Yuri Rosenberg [4]  ,  Michael Karpovski [1]  ,  Eran Sterer [3]  ,  Yoram Dagan [1]  ,  Gregory Rozenberg [1]  ,  Alexander Palevski [1]  
[1] Raymond and Beverly Sackler School of Physics and Astronomy, Tel-Aviv University
[2] Department of Material Science and Engineering, Tel-Aviv University
[3] Physics Department, Nuclear Research Center Negev
[4] Wolfson Applied Material Research Center, Tel-Aviv University

GeSb2Te4 (GST) is a high chalcogenide phase change material that has attracted considerable attention for the last decade due to its tunable Metal to Insulator Transition and many potential applications in the electronics industry.

We present our study of compressed GST and report on the discovery of superconductivity in its amorphous state and several crystal states such as bcc and orthorhombic. By performing transport measurements we demonstrated superconductivity attributes such as vanishing resistance below critical temperature, upper critical magnetic field and critical current density. The various superconducting transitions are well correlated with the observed structural transitions.

We showed that the superconductivity transition temperature Tc continuously increases with the applied pressure reaching a maximum Tc =6K at P=20 GPa for the amorphous-GST, whereas the critical temperature of bcc-GST reaches a maximum Tc =8 K at 30 GPa.