The X-ray-induced, nonthermal fluidization of the prototypical SiO2 glass is investigated by X-ray photon correlation spectroscopy in the small-angle scattering range. This process is initiated by the absorption of X-rays and leads to overall atomic displacements which reach at least few nanometers at temperatures well below the glass transition. At absorbed doses of ∼5 GGy typical of many modern X-ray-based experiments, the atomic displacements display a hyperdiffusive behavior and are distributed according to a heavy-tailed, Lévy stable distribution. This is attributed to the stochastic generation of X-ray-induced point defects which give rise to a dynamically fluctuating potential landscape, thus providing a microscopic picture of the fluidization process.
F. Dallari, A. Martinelli, F. Caporaletti, M. Sprung, G. Baldi, & G. Monaco, Stochastic atomic acceleration during the X-ray-induced fluidization of a silica glass, Proceedings of the National Academy of Sciences, 120(2), e2213182120 (2023)
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