Visualization of Atomic-Scale Motions in Materials via Femtosecond X-Ray Scattering Techniques

We review current progress with respect to ultrafast, atomic-scale resolution X-ray scattering studies of materials. In the last decade, advances in sources and techniques have opened up new possibilities for probing the dynamics of how materials change in situ and in real time. These developments have enabled direct measurements of the first primary steps in how complex/functional materials transform and the flow of energy between different degrees of freedom. Unique insight into the mechanisms underlying how materials function is obtained through these studies. An outlook on future developments and new opportunities is also presented.