Current and future directions in probing structural dynamics and transport of metallic glasses

Abstract

In this article, we discuss the challenges in assessing dynamics and structural changes of metallic glasses as amorphous out-of-equilibrium materials by means of coherent x-ray scattering. We focus on the fundamental understanding of the x-ray photon correlation spectroscopy (XPCS) technique and on how such an experimental probe may facilitate a deeper quantitative understanding of the underlying structural fluctuations occurring within the amorphous solid. Furthermore, we present how atomistic simulations and simulated x-ray photon correlation spectroscopy experiments can guide the interpretation of experimentally measured data. We conclude with a broader perspective on how contemporary advances in modeling, detector technology, and high flux x‑ray sources are transforming the study of glassy dynamics, enabling access to wider time and length scales and thus offering new avenues to probe the broad relaxation spectrum and complex nonequilibrium relaxation processes characteristic of amorphous solids. The X-ray photon correlation spectroscopy method uses coherent X-ray to probe structural relaxation processes in bulk metallic glasses by studying the temporal correlations in the obtained speckle patterns The X-ray photon correlation spectroscopy method uses coherent X-ray to probe structural relaxation processes in bulk metallic glasses by studying the temporal correlations in the obtained speckle patterns