Direct observation of structural changes in chemically homogeneous and self-doped metallic glasses upon in-situ ultrafast heating and cooli

Recently, our group has shown the existence of multiple critical cooling rates which generate different types of monolithic metallic glasses. Via fast differential scanning calorimetry (FDSC), using a Au-based MG as an example, we proved that MGs should be classified into two types of amorphous/monolithic glass. The first type, termed self-doped glass (SDG), forms quenched-in nuclei or nucleation precursors upon cooling, whereas in the so-called chemically homogeneous glass (CHG) no quenched-in structures are found. Although the kinetics of these processes and the stability of the crystalline structures were established, there is no direct observation of the structural changes. These changes will be investigated by analyzing in-situ X-ray diffraction data (reciprocal space or direct space, i.e. pair distribution functions) as recorded with a fast detector upon rapid heating and cooling with the help of a FDSC chip sensor.