Ultrafast structural transformations in metals studied by time resolved XRD

We have studied ultrafast structural transformations in sub-picosecond laser-excited metals - thin Fe and Pd layers. The temporal evolution of the samples' state was characterized using the x-ray diffraction technique at XFEL facility. The application of the ultrashort (fs) x-ray pulses allowed to direct probe the atomic structure of the sample with an unprecedentedly high temporal resolution of ~500 fs (relevant for the ultrafast rates of studied processes). The experimental results were compared with molecular dynamics simulations. The proposed experimental approach is matching the timescales of experimental and computational studies of structural transformations. It enabled new insight into the atomic-level mechanisms and kinetics of ultrafast phase transitions.