Frey Maximilian, Neuber Nico, Riegler Sascha Sebastian, Cornet Antoine, Chushkin Yuriy, Zontone Federico, Ruschel Lucas Matthias, Adam Bastian, Nabahat Mehran, Yang Fan, Shen Jie, Westermeier Fabian, Sprung Michael, Cangialosi Daniele, Di Lisio Valerio, Gallino Isabella, Busch Ralf, Ruta Beatrice, Pineda Eloi
Chair of Metallic Materials, Saarland University, Saarbrücken, Germany.
Institut Néel, Université Grenoble Alpes and Centre National de la Recherche Scientifique, Grenoble, France.
Nat Commun. 2025 May 13;16(1):4429. doi: 10.1038/s41467-025-59767-2.
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.
几十年来，过冷液体的动力学和玻璃化动力学一直是科学与工程领域积极研究的课题。借助现代探测器技术和高亮度的第四代同步辐射，我们应用温度扫描X射线光子相关光谱法（XPCS）来探测一种铂基金属玻璃形成体在玻璃态、玻璃转变区域和过冷液体中的动力学，时间尺度跨越六个数量级。我们的数据表明，结构α弛豫过程在玻璃态中仍然可以观察到，尽管它部分被原子尺度上观察到的更快的去相关源所掩盖。我们提出了一种方法，将这些发现解释为非均匀类液体和应力驱动的弹道式原子运动的叠加。这项工作不仅扩展了标准等温XPCS探测的动力学范围，还为跨越玻璃转变的α弛豫提供了不同的视角，并深入了解了在金属玻璃和许多非平衡软材料中观察到的密度-密度相关函数的异常、压缩时间衰减。
