Liquid-like versus stress-driven dynamics in a metallic glass former observed by temperature scanning X-ray photon correlation spectroscopy
- Maximilian Frey
- Nico Neuber
- Sascha Sebastian Riegler
- Antoine Cornet
- Yuriy Chushkin
- Federico Zontone
- Lucas Matthias Ruschel
- Bastian Adam
- Mehran Nabahat
- Fan Yang
- Jie Shen
- Fabian Westermeier
- Michael Sprung
- Daniele Cangialosi
- Valerio Di Lisio
- Isabella Gallino
- Ralf Busch
- Beatrice Ruta
- Eloi Pineda
2025-05-13
Since several decades, the dynamics and vitrification kinetics of supercooled liquids are the subject of active research in science and engineering. Profiting from modern detector technology and highly brilliant fourth-generation synchrotron radiation, we apply temperature scanning X-ray photon correlation spectroscopy (XPCS) to probe the dynamics of a Pt-based metallic glass former in the glass, glass transition region, and supercooled liquid, covering up to six orders of magnitude in timescales. Our data demonstrates that the structural α-relaxation process is still observable in the glass, although it is partially masked by a faster source of decorrelation observed at atomic scale. We present an approach that interprets these findings as the superposition of heterogeneous liquid-like and stress-driven ballistic-like atomic motions. This work not only extends the dynamical range probed by standard isothermal XPCS but also adds a different view on the α-relaxation across the glass transition and provides insights into the anomalous, compressed temporal decay of the density-density correlation functions observed in metallic glasses and many out-of-equilibrium soft materials.