2021/04/30 by Florian Spieckermann, Daniel Şopu, Viktor Soprunyuk +11 · 61 citations
Chemistry · Engineering · Materials Science · Physics and Astronomy · #Amorphous metal #Annealing (glass) #Chemical physics #Chemistry #Composite material #Configuration entropy #Crystallization #Diffraction #Glass properties and applications #Glass transition #Material Dynamics and Properties #Materials science #Metallic Glasses and Amorphous Alloys #Optics #Physics #Polymer #Relaxation (psychology) #Structural change #Synchrotron #Synchrotron radiation #Thermodynamics #cond-mat.mtrl-sci
paper · pdf · doi:10.1038/s41467-021-27661-2
published in Nature Communications 13(1), 127 (Nature Portfolio)
openalex publication_date 2022/01/10 · arxiv created 2022/01/11 · arxiv updated 2022/01/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Abstract The atomistic mechanisms occurring during the processes of aging and rejuvenation in glassy materials involve very small structural rearrangements that are extremely difficult to capture experimentally. Here we use in-situ X-ray diffraction to investigate the structural rearrangements during annealing from 77 K up to the crystallization temperature in C u 44 Z r 44 A l 8 H f 2 C o 2 bulk metallic glass rejuvenated by high pressure torsion performed at cryogenic temperatures and at room temperature. Using a measure of the configurational entropy calculated from the X-ray pair correlation function, the structural footprint of the deformation-induced rejuvenation in bulk metallic glass is revealed. With synchrotron radiation, temperature and time resolutions comparable to calorimetric experiments are possible. This opens hitherto unavailable experimental possibilities allowing to unambiguously correlate changes in atomic configuration and structure to calorimetrically observed signals and can attribute those to changes of the dynamic and vibrational relaxations ( α -, β - and γ -transition) in glassy materials. The results suggest that the structural footprint of the β -transition is related to entropic relaxation with characteristics of a first-order transition. Dynamic mechanical analysis data shows that in the range of the β -transition, non-reversible structural rearrangements are preferentially activated. The low-temperature γ -transition is mostly triggering reversible deformations and shows a change of slope in the entropic footprint suggesting second-order characteristics.