The progress on the development of femtosecond structural probes during the last sixteen years has been tremendous. Current ultrafast structural probes provide us with the temporal and spatial resolutions required to enable the observation of atoms in motion during chemical reactions and phase transformations. During my talk I will cover the technical progress that made this new level of acuity possible and give a survey of the new insights gained from an atomic level perspective of structural dynamics through the implementation of femtosecond electron sources. Atomic level views of the simplest possible structural transition, melting, are going to be discussed for a number of systems.1-3 Optical manipulation of charge distributions and effects on interatomic forces can be directly observed through the ensuing atomic motions to give a remarkable view of the extraordinary degree of cooperativity involved in low-dimensional materials.4 Different compression approaches have made it possible the generation of ultrashort and ultrabright electron pulses with an effective brightness close to that of fs hard X-ray pulses produced by free electron lasers. I will finalize my talk showing recent results obtained for a labile organic crystal composed by light scattering centers.5 Here, we implemented a recently developed ultrabright femtosecond electron source to obtain an atomically-resolved movie of the relevant molecular motions driving the photo-induced insulator-to-metal phase transition in the organic charge-transfer salt (EDO-TTF)2PF6. This study illustrates the potential of ultrabright femtosecond electron pulses for probing, with atomic resolution, the primary dynamical processes governing chemical and biological phenomena.References1 Sciaini et al., Nature 458, 56 (2009). 2 Ernstorfer et al., Science 323, 1033 (2009). 3 Harb et al., Phys. Rev. Lett. 100, 155504 (2008). 4 Eichberger, Sch�fer, Sciaini (eq. cont.) et al., Nature 468, 799 (2010). 5 Gao, Sciaini (eq. cont.) et al., Nature, in press.

Ultrabright femtosecond electron diffraction for the study of dynamical phenomena at the atomic level of inspection

246th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.