Year: 2026
Type: preprint
Abstract: Understanding the microscopic mechanisms underlying polyamorphic transitions requires simultaneous knowledge of thermodynamic and structural evolution, which has remained experimentally inaccessible. Here, we combine chip-based fast differential scanning calorimetry with high-energy synchrotron X-ray diffraction to simultaneously probe the thermodynamic and structural evolution during the polyamorphic transition of a Pd-Ni-P metallic glass. Correlating heat-flow signals with the corresponding structural evolution during both heating and cooling reveals a direct relationship between thermodynamic evolution and medium-range structural ordering. Based on this relationship, we identify two distinct transition mechanisms. In the glassy state, the transition proceeds continuously through progressive medium-range ordering, accompanied by enhanced thermal stability and strongly temperature-dependent kinetics. In contrast, in the equilibrium supercooled liquid, the transition proceeds through the coexistence of distinct amorphous states, with only a weak temperature dependence of the kinetics. These findings show that atomic mobility governs the transformation pathway by coupling thermodynamic evolution to structural ordering, providing new insights into polyamorphic transitions in nonequilibrium amorphous systems.
Source: arXiv (Cornell University)
Institutions: Centre National de la Recherche Scientifique, European Synchrotron Radiation Facility, Institut Néel, Université Grenoble Alpes, University of Padua, Material Physics Center, Donostia International Physics Center, Technische Universität Berlin, Chinese Academy of Sciences, Institute of Physics, University of Chinese Academy of Sciences
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7223655314