Investigating the effect of shock-compression on glass transition in Germanium-Selenium glass Systems

The nature of the rigid (stiffness) to floppy (flexible) phase (intermediate phase) transition in network glasses continues to be one of the central issues in glass science.  we have successfully observed intermediate phase in Ge_xSe_1-x (x = 0.225) glass samples at a glass transition temperature (Tg) of 220^o C. In this work, we report postmortem studies on shock-compressed Ge-Se glasses. The dynamic compression experiments were performed using a laser-driven flyer plate system. This high-throughput technique can incorporate in situ, real time spectroscopy and high speed, high resolution images collected during shock wave propagation through the glasses. To investigate any permanent changes due to compression, glass samples were characterized before and after the experiments. The flyers had impact velocities of 3.5 km/s, corresponding to pressures of ~ 24 GPa. The impacted glass samples were recovered after shock for postmortem analysis with modulated differential scanning calorimeter and x-ray diffraction at room temperature. The results have shown changes in glass transition temperatures, evidence of permanent changes in the crystal structures of the compressed glasses. The study is extremely important in order to develop new glass materials with advanced properties.