A dynamical view at polyamorphism in phase change materials

We propose here to use X-ray Photon Correlation Spectroscopy (XPCS) to give a new look at polyamorphism and perform the first investigations that study the atomic motion during a glass-glass transition in the Ge2Sb2Te5 phase change material (PCM). This polyamorphic transition is a semiconductor-to-metal transition accompanied by a four order of magnitude drop of the electrical resistivity, which is comparable with the jump in resistivity usually associated during the amorphous-to-crystalline transition used in current phase-change memories. The results will unveil new crucial features on the ongoing relaxation processes in these technologically important materials and will also strongly improve our knowledge on polyamorphism in glasses.