Titre : Pressure dependence of the collective motion in glasses studied with coherent x-rays
Institut Néel, Salle F418 (Erwin Bertaut)
Résumé : X-ray Photon Correlation Spectroscopy (XPCS) is a spatio-temporal coherent X-ray scattering technique that probes slow collective dynamics at the nanometric and atomic scale based on the observation of fluctuating far-field speckle patterns [1].
This technique has been successfully applied to the investigation of slow relaxation processes occurring in disordered materials undergoing dynamical arrest, polyamorphism and aging, such as supercooled liquids [2,3], glasses [4], and concentrated colloidal suspensions [5]. The Extreme Brilliance Source (EBS) upgrade of synchrotron ESRF has extended dramatically the dynamical range of XPCS with a considerable increase of the coherent flux at higher photon energies, making
possible in-situ high pressure (HP) studies of the atomic motion in complex systems.
In this talk, I will present recent experimental results on the atomic motion in a metallic glass obtained with HP-XPCS at ESRF-EBS, and I will also illustrate some of the future scientific possibilities offered by this technique in the field of high pressure science in glass formers.
[1] A. Madsen, A. Fluerasu and B. Ruta, Synchrotron Light Sources and Free-Electron Lasers, Springer International Publishing, 2020, pp. 1–21.
[2] B. Ruta et al. Phys. Rev. Lett. 125, 055701, 2020
[3] S. Hechler et al. Phys. Rev. Mat. Phys. Rev. Mat. 2, 085603, 2018
[4] B. Ruta et al. Topical Review, J. Phy.: Cond. Matter 29, 503002, 2017
