Predicting Complex Relaxation Processes in Metallic Glass

Abstract

Relaxation processes significantly influence the properties of glass materials. However, understanding their specific origins is difficult, even more challenging is to forecast them theoretically. In this study, using microseconds molecular dynamics simulations together with an accurate many-body interaction potential, we predict that an Al${}_{\text{90}}$Sm${}_{\text{10}}$ metallic glass would have complex relaxation behaviors: In addition to the main ($\alpha$) relaxation, the glass (i) shows a pronounced secondary ($\beta$) relaxation at cryogenic temperatures and (ii) exhibits an anomalous relaxation process (${\alpha }_2$) accompanying $\alpha$ relaxation. Both of the predictions are verified by experiments. Computational simulations reveal the microscopic origins of relaxation processes: while the pronounced $\beta$ relaxation is attributed to the abundance of string-like cooperative atomic rearrangements, the anomalous ${\alpha }_2$ process is found to correlate with the decoupling of the faster motions of Al with slower Sm atoms. The combination of simulations and experiments represents a first glimpse of what may become a predictive routine and integral step for glass physics.

References in corpus (17)

• Theoretical perspective on the glass transition and amorphous materials
• String-like Clusters and Cooperative Motion in a Model Glass-Forming Liquid
• Atomic-scale relaxation dynamics and aging in a metallic glass probed by X-ray photon correlation spectroscopy
• The Relationship of Dynamical Heterogeneity to the Adam-Gibbs and Random First-Order Transition Theories of Glass Formation
• Relaxation decoupling in metallic glassy state
• Relaxation and physical aging in network glasses: a review
• Nonmonotonic Aging and Memory Retention in Disordered Mechanical Systems
• A Double-Transition Scenario for Anomalous Diffusion in Glass-Forming Mixtures
• Unveiling the structural arrangements responsible for the atomic dynamics in metallic glasses during physical aging
• The relaxation dynamics of a viscous silica melt: II The intermediate scattering functions
• Johari-Goldstein relaxation far below Tg: Experimental evidence for the Gardner transition in structural glasses?
• Nucleation Kinetics in Al-Sm Metallic Glasses
• Critical Analysis of an FeP Empirical Potential Employed to Study Fracture of Metallic Glasses
• Unconventional phase selection in high-driven systems: A complex metastable structure prevails over simple stable phases
• Possible origin of $\beta$-relaxation in amorphous metal alloys from atomic-mass differences of the constituents
• Effects of dopants on the glass forming ability in Al-based metallic alloy
• Spatially-correlated Site Occupancy in the Nonstoichiometric Meta-stable ε-Al60Sm11 Phase during Devitrification of Al-10.2 at.% Sm Glasses

Cited by in corpus (3)

• Fast Dynamics in a Model Metallic Glass-forming Material
• Universal Origin of Glassy Relaxation as Recognized by Configuration Pattern-matching
• Johari-Goldstein $\beta$ relaxation in glassy dynamics originates from two-scale energy landscape