Fig. 1: The in-situ X-ray diffraction intensity I(Q) under compression from the ambient pressure to ~10 GPa.

a GeSe and b GeTe The GeSe remains fully amorphous up to 10.0 GPa, while GeTe is partially crystalized at 3.4 GPa. The inset of b is the result of the Rietveld refinement of GeTe at 7.5 GPa with the experimental data (red dots), the calculated data of the cubic GeTe (blue line), the background (light blue line), and the residuals between experimental and calculated data (purple line).