Time resolved X-ray diffraction and non-thermal inelastic X-ray scattering

Atomic processes like e.g. molecular vibrations, chemical reactions or phase transitions happen on picosecond down to femtosecond time scales. Novel pulsed X-ray sources or alternatively ultrafast X-ray detectors allow the investigation of these processes in real time. A powerful tool for the investigation of the dynamics in crystalline materials is Time Resolved X-ray Diffraction (TRXD). As an example the authors present the measurement of "phonon branch folding" in a GaSb/InAs superlattice by means of TRXD. In the second part we look forward to the near future of TRXD. X-ray scattering from coherent acoustic and optical phonons has recently become describable within the framework of dynamical diffraction theory. This theory provides the means for the detailed modelling of how various lattice dynamical processes manifest themselves in the diffracted X-ray signal. Simulations are presented showing the effects of coherent acoustic and optical phonons on the rocking curve of quartz (010).