Anti-aging and avalanche dynamics in ultrastable metallic glasses by X-ray photon correlation spectroscopy
von Martin Lüttich
Datum der mündl. Prüfung:2023-05-09
Erschienen:2024-04-23
Betreuer:Prof. Dr. Konrad Samwer
Gutachter:Prof. Dr. Konrad Samwer
Gutachter:Prof. Dr. Matthias Krüger
Dateien
Name:thesis-for-publication_online.pdf
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Zusammenfassung
Englisch
Within this thesis, structural relaxation dynamics of vapour deposited as well as conventionally produced metallic glasses are studied. Vapour deposition enables to crucially tune the surface diffusion during the deposition process, so metallic glasses with much lower potential energy can be fabricated – so-called ultrastable metallic glasses (UMGs). X-ray photon correlation spectroscopy (XPCS) studies of UMGs reveal a particular anti-aging behaviour upon annealing, which underlines the intrinsic low potential energy of UMGs. Furthermore, a new data processing method was developed in order to analyse the statistics of relaxation time changes along with the evolution of the relaxation behaviour, uncovering evidence for avalanche-like dynamics upon non-directional excitation of local rearrangements in annealed vapour deposited metallic glasses.
Keywords: anti-aging; metallic glass; dynamics; XPCS; ultrastable metallic glass; UMG