Intermittent cluster dynamics and temporal fractional diffusion in a bulk metallic glass
- Inspired by the ability to track atomic-scale dynamics with x-ray photon correlation spectroscopy (XPCS)1 and recent results of long-term atomistic simulations on material transport2, we reveal here an unprecedented spectrum of short- and long-term relaxation dynamics. Tracked along a 300 000 s long isotherm at 0.98Tg, a Zr-based bulk metallic glass exhibits temporal fluctuations that persist throughout the entire isotherm, demonstrating a continuous heterogeneous dynamics at the probed length scale. In concert with microsecond molecular dynamic simulations, we identify intermittent cluster dynamics as the origin for temporal signatures in the corresponding intensity cross-correlations. Despite temporally heterogeneous aging, the Kohlrausch-Williams-Watts functions is well suited to capture the average intermediate relaxation time regime, but at very long time scales an asymptotic power-law better describes the data. This indicates anomalous diffusion and gives overall strong evidenceInspired by the ability to track atomic-scale dynamics with x-ray photon correlation spectroscopy (XPCS)1 and recent results of long-term atomistic simulations on material transport2, we reveal here an unprecedented spectrum of short- and long-term relaxation dynamics. Tracked along a 300 000 s long isotherm at 0.98Tg, a Zr-based bulk metallic glass exhibits temporal fluctuations that persist throughout the entire isotherm, demonstrating a continuous heterogeneous dynamics at the probed length scale. In concert with microsecond molecular dynamic simulations, we identify intermittent cluster dynamics as the origin for temporal signatures in the corresponding intensity cross-correlations. Despite temporally heterogeneous aging, the Kohlrausch-Williams-Watts functions is well suited to capture the average intermediate relaxation time regime, but at very long time scales an asymptotic power-law better describes the data. This indicates anomalous diffusion and gives overall strong evidence for temporal fractional diffusion in metallic glasses. We discuss these results in terms of the underlying structural fast and slow relaxation modes and their manifestation in the temporal form of the structural decorrelations.…
Autor*innen: | Robert MaaßORCiD |
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Koautor*innen: | Birte Riechers, Amlan Das, Zengquan Wang, Eric Dufresne, Peter M. Derlet |
Dokumenttyp: | Vortrag |
Veröffentlichungsform: | Präsentation |
Sprache: | Englisch |
Jahr der Erstveröffentlichung: | 2023 |
Organisationseinheit der BAM: | 5 Werkstofftechnik |
5 Werkstofftechnik / 5.0 Abteilungsleitung und andere | |
DDC-Klassifikation: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurwissenschaften und zugeordnete Tätigkeiten |
Freie Schlagwörter: | Dynamics; Metallic glass; Structure; Transport |
Themenfelder/Aktivitätsfelder der BAM: | Material |
Material / Degradation von Werkstoffen | |
Material / Materialdesign | |
Veranstaltung: | 9th IDMRCS |
Veranstaltungsort: | Chiba, Japan |
Beginndatum der Veranstaltung: | 12.08.2023 |
Enddatum der Veranstaltung: | 18.08.2023 |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 26.07.2024 |
Referierte Publikation: | Nein |
Eingeladener Vortrag: | Ja |