X-ray Induced Dynamics in Borate Glasses with Different Network Connectivity

Hard x rays induce atomic dynamics in oxide glasses at doses low enough that the average structure is unchanged. X-ray photon correlation spectroscopy is used here to study this effect in a series of alkali borate glasses characterized by different network connectivity. The product of the x-ray dose rate per atom and the decay time of the density correlation function is a sample-dependent parameter with the dimensions of an energy: It varies between a fraction of eV and few tens of eV and is sensitive to the network connectivity of the glass. It can then be used to access some bonding information also in cases where the x rays perturb the material, a regime of great interest in modern x-ray-based experiments.