Researches on pressure-induced structural evolution using multiple synchrotron X-ray techniques

       The researches on behavior of crystalline and non-crystalline materials under high pressure extreme conditions are long time hot topics in condense matter physics. Many interesting behavior, such as pressure-induced phase transitions, amorphization of solid forms, liquid-to-liquid transformation, pressure-induced polyamorphism from low- to high-density states of glasses, and the dynamics of pressure-induced crystallization were reported but not fully understood. In this presentation, several selected noncrystalline systems were in situ studied under high pressure using cutting-edge synchrotron microtomographic, x-ray diffraction (XRD) as well as pair distribution function (PDF) techniques in diamond anvil cell and large volume press. XPCS technique will be used to study the relaxation behaviors of metallic glasses upon compression and heating. Several typical crystalline materials, including powder and single crystal samples, will be presented, for the research topic on phase transitions, isostructural transition, pressure tune charge transfer and mixed valance modifications behaviors, and negative linear compression at over 100 GPa conditions. 3 dimensional X-ray diffraction (3D-XRD) technique will be introduced for the study on the pressure induced phase transition in powder Fe sample within diamond anvil cell (DAC). The micro focusing beam size at range of couple microns could help us to create diffraction tomography of the different phase in sample during phase transition process under pressure conditions.