The movement of single atoms is a fundamental issue in materials science. The fabrication, specific properties and the stability of materials can be significantly improved with knowledge about atomic movement. Numerous properties of materials can be attributed to the single atom motion. Studies of diffusion mechanisms on the atomic scale are challenging despite a number of well-established methods which can be applied to experimentally investigate diffusion in solid state systems. Drawing conclusions from macroscopic measurements on the actual microscopic dynamics is a highly indirect procedure. Due to the relatively long timescales where atomic motion takes place, scattering techniques that rely on a high energy-resolution can only resolve fast processes. The greatest challenge is, however, that only a small number of selected isotopes are accessible to these methods which strongly limits their use. A new method not restricted to certain isotopes and capable of detecting slow diffusion is therefore required. As we have shown in our previous projects these requirements are met by atomic-scale X-ray photon correlation spectroscopy (aXPCS). Former grants served the implementation of XPCS as the preferred method for studying atomic dynamics mainly in crystalline phases. The current project is devoted to studying another very intriguing form of matter, namely the family of glasses. 

Glasses are an active and promising field of research. Understanding disordered solids on a fundamental level and particularly understanding ion conduction in these materials still presents a fundamental challenge. The random formation of structural networks is an important model for explaining the glass forming ability of many materials. The dynamics of basic network components play a key role in decoding puzzling properties of this form of matter like ionic dynamics. Considerable progress with solid-oxide fuel cells, batteries and supercapacitors, in electrochemical sensors and functional polymers has been achieved recently. Even so, the basic concept of ion transport in disordered materials remains poorly understood. This is due to the fact that there is no simple, widely accepted model of transport. Considering the current strong interest in the field and the plethora of experimental and theoretical works it is striking that, in contrast to transport properties in crystalline matter, there is no general consensus on several fundamental questions. It is our aim to shed light on the motion of ions on the atomic level in ionic conducting boron and silica glass and we are confident that the insights gained can be transferred to other ionic glasses.

In our project we will profit from the continuously increasing brilliance of existing synchrotron sources like the upgrade of the ESRF in Grenoble, which was just completed and from new sources like PETRA III in Hamburg.