Probing the dynamics of B2O3 across the glass transition: an X-ray photon correlation spectroscopy study

X-ray photon correlation spectroscopy is used to study the dynamics of the glass former across the glass transition temperature, . The obtained data confirm that while the structural relaxation drives the density rearrangements in the liquid phase, a beam-induced dynamics is the dominant effect around and below . The use of a hybrid photon counting detector allows us to obtain high-quality correlation functions with a characteristic decay time down to a second. The characteristic time of the induced dynamics displays a linear dependence on the inverse of the absorbed X-ray power over the whole observed range, i.e. up to powers of 0.2 eV/atom/s. Up to these values, then, an X-ray irradiated glass sample explores structurally equivalent configurations on a timescale dictated by the absorbed power.