X-ray induced amorphous-amorphous transition in vitreous silica

We propose an x-ray diffraction experiment to investigate the structural evolution of v-SiO2 under x-ray irradiation. Recent x-ray photon correlation experiments have revealed that the x-ray beam simultaneously pumps and probes the dynamics of oxide glasses at temperatures where the spontaneous structural relaxation is frozen. The observed dynamics is accompanied by a progressive rearrangement of the glass structure, which evolves towards a different amorphous configuration. This behaviour suggests the existence of a x-ray induced amorphous-amorphous transition. A detailed structural investigation is thus pivotal to elucidate the microscopic nature of the x-ray induced dynamics in glasses.